A rap song leaks out in tinny spurts from the earphones; the skinny kid wearing them stands transfixed in the ghostly fluorescent light of the packed No. 8 bus heading up Greenmount Avenue. Behind him, a man in a corduroy souvenir-day Orioles cap is snoring in one of the handicapped seats, propped between two obliging and able-bodied fellow passengers.

Even though it's a chilly night, the smoked glass makes the city outside look hot, sultry and sinister. A blond young man, his unblinking eyes focused on the air a few inches in front of him, lurches out of his blue plastic seat and grabs an advertising postcard about "Getting a Better Career." He flops back, puts a finger to his lips and studies his new-found job opportunities.

Everyone on the bus, it seems, is looking for something: a thumping backbeat, a better job, a little shut-eye or just a peaceful ride home.

My quest is different. I've paid my $1.10 to board the northbound No. 8 on a pilgrimage in search of the soul in the machinery, the warts-and-all character of the great blue-and-white whales that weave along asphalt currents past the city's reefs of concrete, Formstone and red brick.

While they are unglamorous, ungainly, unlovely and mostly unloved, for most purposes the city's 900 Grumman Flxible buses are its mass transit network. The rest -- subway, light rail, commuter trains, taxis, car pools, bicycles, skateboards, what have you -- are just frills, expensive options on the sturdy base model.

Baltimore's 14.2-mile Metro line serves fewer than 50,00passengers daily, and the Mass Transit Administration is building a 27.5-mile light rail system that, by 2005, is expected to carry another 34,000 passengers.

By comparison, buses cruise 1,227 miles of routes in the metropolitan area, carrying more than 290,000 passengers per day. That's more than three times the number of people the city's two rail projects are expected to carry 14 years from now.

AFTER MY FIRST FEW MONTHS AS THE Sun's transportation reporter, I realized that despite having commuted by car, subway and train in three states during my working life, I knew next to nothing about buses in Baltimore or anywhere else.

So I set out to learn, first for a month as an occasional commuter armed with a bus pass. Then, when I wound up using my car too often, I decided to go cold turkey -- I quit driving for a week and relied on buses exclusively. (With only one lapse, when I was dispatched to report on a pancake house stickup on deadline).

In preparation, I locked up my 1983 Plymouth Reliant, bought a couple of $10.50 packets of bus tokens and picked up a 1 1/2 -inch-thick stack of schedules from MTA headquarters near Lexington Market. My riding wasn't exhaustive or scientific. I didn't ride all the lines at all hours, I just used the buses I needed to get where I was going. There were no surveys or polls -- I talked to drivers and other riders and kept my eyes open.

What I found was a no-frills system, heavily used by lower-income and handicapped people, with just enough buses on enough routes to get me most places I wanted to go in a reasonable time. It's a system that rewards planning and patience, but is not suited for spur-of-the-moment trips or joy riding. Waits, especially off rush hour, can be long, and to avoid them the complicated route schedules must be deciphered and rigorously obeyed.

There were cramped seats and grumpy drivers who, nearing the end of their route, roared by passengers rather than stopping to pick them up, apparently because they were in a hurry to get off shift. One driver complained bitterly about being required to show up for work on time and being ordered to drive his bus in the snow.

But I also found drivers who chatted with and charmed their passengers. There were buses that were islands of peace amid the tumult of traffic. And, for the curious passenger not engrossed in a newspaper or a Walkman, the buses sometimes provide a mirror of the city, creating quickly vanishing replicas of the neighborhoods they pass through.

And buses were one of the few places in this city of neighborhoods where people from different neighborhoods mix -- where lawyers sit next to laborers, college students next to teen-age fast-food workers.

"You always run into people on the buses and everything: It's pretty sociable," says Duane Hemphill, riding the No. 8 up Greenmount Avenue one evening after work.

"Plus it builds a strong will in just conversing on the bus. It keeps you up, up on your feet. It keeps you lively, too. It's competitive. You know. It's competitive in the sense you've got to learn to get along with people. You've got to learn to be non-offensive. . . . Get your way through without pushing or shoving."

WHILE THE BUS SYSTEM SEEMS healthy now, it is showing symptoms of potential trouble.

The state of Maryland, not Baltimore City, owns and runs the city's mass transit system. That means that when it comes to financing, the pockets are deeper. But there may also be less sympathy among the decision makers for the ordinary rider.

The state legislature requires the MTA, part of the state Department of Transportation, to earn at least 50 percent of its operating costs from bus and subway fares -- which this year it just barely managed to do.

To cut spending, the MTA has trimmed about 5 percent of its bus route miles in the past four years, says MTA Administrator Ronald J. Hartman. Base fares, meanwhile, have risen almost 47 percent since 1986 -- from 75 cents to $1.10. (The total fare depends on how far passengers travel. A trip from downtown to the outermost MTA zone now costs $2.)

The increases have made Baltimore's transit system one of the more expensive in the United States. And the MTA has plans to increase those fares every year for the indefinite future to make ,, sure it can earn 50 cents of every dollar it costs to run the system.

Higher fares can persuade people not to ride. Daily transit patronage has dropped since last July by about 2.6 percent compared with a similar period in 1989-1990 -- a 1.5 percent fall for buses, and a 3.5 percent decrease for the Metro. Mr. Hartman isn't sure what's causing the slow erosion of riders, but thinks it may be related to the area's weak economy.

Most buses are now relatively new and in good shape, thanks to an MTA policy of buying 80 new buses a year to replace those that wear out. But because of the Department of Transportation's budget problems, which have at least temporarily halted numerous highway projects around the state, the MTA's budget for replacing buses has been slashed: No new buses will be purchased in fiscal 1991, MTA officials say, while only 50 will be purchased in fiscal 1992.

The danger is that the cost-cutting could trigger a dangerous spiral of higher fares and cuts in service, leading to a loss of more riders, leading to more revenue losses, leading to higher fares and so on.

At some point, if buses run too infrequently along too few routes serving too few passengers, they lose the critical density needed to form a useful system. Which would leave Baltimore without any real mass transit at all.

Public transit is needed, and not just for the handicapped and poor and city school students. Existing streets and highways are overcrowded, or close to it, even in Baltimore -- one of the least traffic-choked cities in the Northeast. To save the state's remaining forests and farms and the Chesapeake Bay, state officials are trying to direct growth to already urbanized areas.

To remain livable, cities everywhere -- Baltimore included -- are going to need more extensive, efficient and attractive public transit systems. The MTA's bus system -- supplemented by the Metro and light-rail lines -- forms the fragile nucleus around which that future system is likely to grow.

WHEN I FIRST BEGAN RIDING BUSES for this story, I was a cowboy -- roping the first bus to come along that, judging by its destination sign, looked like it was headed in my general direction. This strategy can work, in a city where buses run frequently along numerous parallel routes. But it's a flop in Baltimore, where lines quickly diverge along thoroughfares that radiate out of the city center like spokes from the hub of a wheel, and buses run frequently only during rush hours.

Most non-rush-hour buses run only every 30 minutes or so. Waiting at one of the system's 8,000 bus stops and not being sure when to expect to get picked up can feel like drifting in the Atlantic hoping to spot a passing ocean liner. My first 20-minute wait one icy evening on Charles Street cured me of riding without first consulting a schedule. But I still hadn't learned to carry one with me everywhere.

A few days later, I was waiting for my regular commuting bus, the No. 11 "Towson State" or "Rodgers Forge," which travels along the North Charles Street corridor, when a No. 11 arrived marked "Bedford Square." I figured "Bedford Square" was some landmark near Towson and I boarded.

Of course, as everyone else in Baltimore probably knows and the route map clearly shows, Bedford Square is on Charles Street south of Cold Spring Lane -- about 2 1/2 miles short of my stop. The bus halted and I glumly de-bussed. It was cold and dark and the only way to keep warm was to keep moving. So I trudged north on Charles Street, peering over my shoulder for a big

friendly Blue and White. I ended up trekking all the way home.

Another miserable evening I waited on a nearly deserted Calvert Street around 7 p.m. for the No. 61 bus, which was supposed to drop me off on University Parkway near Johns Hopkins University. A No. 71 bus came by instead, with the sign "Johns Hopkins."

I jumped aboard, and it wasn't until the bus turned and roared under the Jones Falls Expressway that I realized it was heading for Johns Hopkins Hospital in East Baltimore. During my walk past the SuperMax maximum-security "adjustment" center by the State Pen I prayed, promising God that if I lived I would never again board an unfamiliar bus.

So I became a scholar of bus schedules, carefully deciphering their asterisks and footnotes and map notes, which detail differences in routes and service frequency that seem subtle. But a misreading can strand you blocks -- or even miles -- from your destination.

The recorded data on the bus system's computerized information system, available at 539-5000, lacks the detail needed to be useful. The recorded messages provide only very general information -- that, for example, a particular bus will pass every five to 10 minutes during rush hours. That doesn't help you decide when to leave the house, or figure out how to time connections from one bus to another.

Also, callers who use the computer answering device need to know the bus route number before they call. If you don't know, you have to hang on through the computer spiel to talk to a live operator. Callers are assured that if they hang on the line, an operator will help them. But the system receives 4,000 to 6,000 calls a day, according to the MTA. Waits for operators can be excruciatingly long. One afternoon in February I waited seven minutes for the next available human being before slamming down the receiver. Other riders reported that they typically wait from five to 15 minutes to get an operator.

ONCE ABOARD THE RIGHT bus, it's a matter of sitting back and relaxing. At least in theory. The molded plastic seats have thin, vinyl-covered cushions and seem designed for people with plump posteriors and very short legs.

Drivers can be merciful or cruel. Tom Grizzard, a 44-year-old copywriter with T. Rowe Price, is a self-confessed "religious" rider who declares that the Baltimore system "floods me with options." But he adds he gets queasy when drivers slam on brakes, lurch into turns or race over heavily potholed roads. "Sometimes you get the idea they're out to make you throw up by the time you get downtown."

The better the driver, he says, the slower he pilots his 27,000-pound craft over a section of Homeland Avenue with more craters than the surface of Mars. "You want to be sure your teeth aren't touching when you go over that road," he says, unless you want a chipped tooth.

The system's 1,449 full- and part-time bus drivers can appear friendly or gruff, patient or curt, eager to answer questions or bored out of their skulls. Some know their regular passengers. Some ignore everyone but fellow drivers they pass on the streets. Sometimes bus drivers decide they know where a rider wants to go better than the rider does. Once I was waiting on Charles Street for a northbound bus, when, after some frantic arm-waving, the bus stopped a good block away from my stop -- and only, apparently, to let out a passenger.

When I ran up to the door, the burly driver seemed annoyed. "This bus isn't going by GBMC (Greater Baltimore Medical Center)!" he snapped as I climbed the steps, apparently deciding that I either looked sick or was dressed like a hospital employee.

A little stunned, I replied that I knew the route.

Ralph Sanders and his wife, Jean, who both commute from Federal Hill to Annapolis every day, said bus drivers who are new to a route sometimes will miss stops or wander down the wrong street, forcing passengers to walk long distances to get to their destination.

This is an inconvenience for some passengers. For the Sanderses, who are both blind, it can be disorienting and a major headache. Mr. Sanders says the MTA itself sometimes gets confused about scheduled detours -- for instance, leaving up signs advising riders that a stop is temporarily closed long after the bus has returned to its normal route.

The Sanderses say drivers also don't always call out stops -- a minor convenience for most riders, who might be engrossed in a book, but a necessity for the blind. And drivers don't always announce their route number to blind people waiting at the curb. "For us, that's a major aggravation," Mr. Sanders says. "Particularly when you have a number of buses go by. You're almost hoarse from yelling, 'What bus is this?' "

One driver who passes their regular morning stop always refuses to tell the Sanderses the number of his bus. "He always says, 'This isn't the bus you want!' " Mr. Sanders says. "He doesn't know. Maybe some day we might want to use that line."

The Sanderses don't blame the drivers. They blame MTA management. "We've come to the conclusion that MTA executives don't do what you're doing: that is, ride the buses, except when they're on inspections," Mr. Sanders says.

(Mr. Hartman, the MTA administrator, says he rides the bus to work every day and all his managers are required to ride at least four times a month. But, he adds, some may have been "slacking off" in recent months.)

Some drivers, meanwhile, are frustrated and angry. One, who says he's likely to get fired if his name appears in the paper, complains that the MTA "makes you feel like you're just a number." MTA management, he says, is obsessed with the enforcement of petty rules, and metes out harsh punishment to drivers who show up a few minutes late for work or are accused of rude behavior by passengers. There aren't enough open restrooms on routes, he says, and drivers are forced to work in snowstorms, when a number of buses always get stuck. "This is not an emergency job," he says. "This is not an emergency vehicle." Mr. Hartman, meanwhile, says he makes no apologies for enforcing rules that make the system run more reliably.

Some drivers are a joy to ride with. On the No. 61 line one morning, a woman boarded with a plate covered by aluminum foil. "What kind of cake is that?" asked the veteran driver, Roy W. Dick, as he rolled up Calvert Street.

"Orange nut," she replied.

"I've been called a nut, but never an orange nut," Mr. Dick said, between calling out stops. Everyone in earshot was smiling.

AT AROUND 8:45 A.M. EVERY weekday morning, the twice-a-day No. 11D bus heads up Charles Street and turns down Bellona Avenue. It is what some riders call "The Maid's Bus," because it carries domestics, day-care workers and maintenance people from their city neighborhoods to the exclusive Baltimore County communities of Ruxton and Riderwood, full of stately homes scattered through wooded hills.

The bus is always jammed, mostly with women in their 30s and 40s, and everyone seems to know everyone else. The morning I boarded, many of the passengers were laughing and chatting about their weekend plans.

As people bundled up and walked toward the hissing doors, their friends called to them. "Have a good weekend!"

"You all have a good day now!"

"Behave yourself!"

Doris Alexander, a woman with a light gray frosting on her hair who works at Kiddie College, a Ruxton day-care center, has been riding the line for more than 20 years. "We have fun on the bus," Ms. Alexander says. "It's like we're going on a picnic every day."

THE MTA SAYS THAT BUSES arrive within two minutes of their schedule about 80 percent of the time. The number sounds about right, but is less important than it seems to experienced bus riders. Sometimes I was a couple of minutes late for the bus, and I was relieved to find the bus was late, too. (Never during my rides was a bus more than 10 minutes behind schedule). It's early buses -- and there were a few -- that get the blood boiling, because those are the ones you miss.

To catch up when they are behind schedule, drivers sometimes plunge wildly through traffic, causing standing passengers to stumble. To avoid being early, drivers simply stall. Aboard a No. 11 headed downtown one sunny Saturday morning, our driver stopped and stared out the window for more than two minutes, then crept down Maryland Avenue at about 15 mph. Meanwhile, the avenue was so deserted that one woman, eight blocks ahead, waited for us in the middle of the street.

Bus riders face their own special challenges.

How, for example, do you let the bus driver know that they want him or her to stop? Or how do you signal that a particular bus isn't the one you are looking for?

Sometimes, riders use an alert look or a nod to signal that they are more than just random pedestrians. I found such subtlety can get you bypassed. Most patrons favor waving a hand, although not too vigorously. Somehow, flagging down a bus the way you would flag down a taxicab seems ridiculous. You're waiting at a bus stop, right? You don't want to insult the driver's intelligence by flapping your arms at him.

Signaling that you don't want a particular bus is harder. Some people hang back away from the curb and pretend to study the shop windows. Others simply avoid eye contact with the driver -- in which case the driver sometimes stops, then roars off in annoyance.

Still other passengers take a more direct approach, shaking their heads or waving their hands in a "no thanks" gesture -- palm outward with a windshield-wiper motion of the arm. (This gesture seemed a little theatrical to me: I settled for catching the driver's eye and shaking my head.)

Once aboard, eye contact among strangers is taboo, but eavesdropping is expected. People who want to read or listen to music sit near the front. Those who want to talk sit in back. On a crowded bus only rude passengers sit in the aisle if the window seat is vacant, because they block the seat for others. Passengers generally avoid sitting in the seats reserved for the elderly or handicapped, even when the bus is nearly empty.

WHEN I BEGAN MY MASS transit odyssey, I had ridden buses, but I was not a bus rider.

I had paid my fare, but I hadn't paid my dues.

I impatiently left the house or office when it was convenient, then cooled my heels at the bus stop. I waited at stops like a car junkie, glancing nervously up the block, then at my watch. I felt naked and alone on the street after dark. I frantically searched pockets for misplaced bus tokens and exact change, and forgot to get transfers.

I rode like a motorist, too, watching the cross-streets pass with what seemed like agonizing slowness. Watching, with sinking heart, the bus follow a route that wandered a bit from the one I would drive home in the evenings and counting the lost minutes. But slowly my internal clock adjusted from dodge-and-weave car time to lumber-along bus time. The gnawing anxiety that the bus would never show up slipped away.

After a few days, I noticed my Charles Street bus stop was next to three art galleries. (One of the exhibits included pictures of Baltimore trolleys and buses.) I began arriving early not from impatience, but just so I could look at the paintings.

I achieved what I imagined was a Zen-like state, a quiet faith that sooner or later the bus would come. I was able to relax and enjoy the ride: to watch the worlds inside and outside the bus change as neighborhoods slipped past and passengers flowed in and out.

It was only then that I realized I had caught the bus.

DOUG BIRCH writes about transportation for The Sun.