Deep below Harvard Square, beyond rattling turnstiles and the vendors hawking popcorn and roasted nuts, Gary Innocent strums a guitar while softly singing French ballads. His audiences come and go - and come and go - as rumbling red subway trains punctuate his songs.
Mr. Innocent is one of hundreds of subway musicians who are as much a fixture on Boston's underground platforms as the rats which skitter along the tracks and the commuters tugging on hats and gloves as they swarm out of trains.
But next week, much of the crooning will cease, and the only subterranean music may be the subways' screeching wheels and the chimes that warn of train doors sliding shut. Starting Dec. 1, subway musicians will no longer be allowed to plug their instruments into electronic amplifiers or play electric keyboards, saxophones, and other horns.
Transit officials say it's a matter of safety - that loud music can drown out messages warbled over public-address speakers. But musicians and their fans say the regulations could dry up the income artists collect, a dollar at a time, and silence songs that make commuting bearable - or at least distract passengers from the strain and stench of subway life.
The rules are sure to transform Boston's true underground music scene, which up to this point has been one of the nation's least regulated. In New York and Atlanta, musicians must audition and sign up for slots; Toronto singers pay a $114 fee; in London, musicians need licenses to croon to commuters "minding the gap." And in Washington, D.C., they're banned altogether: The only songs in travelers' heads are those they're singing to themselves. For Boston musicians, these free-wheeling subway stages were a last foothold of melodic latitude - theirs for a song.
Or almost. Playing Harvard Square's "T" station requires a permit, renewable every three months - and a little loose change. Musicians flip a coin each morning to decide who performs on the most coveted stage: the platform where travelers wait on their way downtown.
The coin-flip winner may be a local music-college student, a blind veteran, or a self-taught guitarist who doubles as a short-order cook. Pop star Tracy Chapman sang underground here while a student at Tufts.
For many commuters, as well as musicians, the rules are a cacophonous shock. Haitian peasant songs, banjo bluegrass, and Joni Mitchell ballads "make the commute much more enjoyable," says Dawn Aberg, a student in Cambridge. "Some of the most exciting music being done comes up from the bottom."
The Subway Performers Program Policy mandates more than unplugged amplifiers: Musicians must pay $25 for a yearly permit, wear "proper clothing," and display photo-ID badges at all times.
"You can't help but think [the rationale] is a pretense," says Mac Craven in the Park Street station under Boston Common. "The [MBTA] messages are garbled anyway."
Alisha Lomasney, leaning against a red steel pole with headphones pulled down around her neck, worries that without amplifiers, trains will drown out the songs: "Taking away speakers takes away the whole point,"
John Ellis, crooning The Cure's "Just Like Heaven" nearby, agrees. "I'm going to feel pretty silly with an acoustic guitar, screaming over the trains," he says. Like Mr. Craven, he's skeptical of the rationale. "They are trying to weed out the undesirables," he says of the Massachusetts Bay Transportation Authority (MBTA) - to clean up the city before the Democratic National Convention lands in Boston next summer.
It was not ever thus. Gov. Mike Dukakis. who rode the "T" to work, found money in the state budget to pay subway musicians - and coax members of the Boston Symphony Orchestra into performing underground, too.
But the era of government funding is gone; these days, musicians rely on tips and CD sales. On a good day, Lisa Housman and Dave Falk can earn as much as $150 singing folk music. They've been playing subways for three years since graduating from Oberlin College and Cornell - and even chose their apartment based on its proximity to Cambridge's Porter Square T stop.
They say their income - which can be more than $150 daily - will fall precipitously under the new rules. "It can be depressing down there," says Ms. Housman. "We make it more peaceful and add a unity to the crowd. People even sing along."
"It's devastating," says Stephen Baird, head of the Street Artists' Guild. And the decision couldn't have come at a worse time, he says: Subway riders are most generous in December. His group has asked the American Civil Liberties Union to challenge the rules on First Amendment grounds, and is circulating petitions.
So far, the MBTA remains unsympathetic. "A subway station is a transit center first; a concert venue is probably last on the list," says spokesman Joe Pesaturo. The rules are among 200 safety changes recommended by a task force appointed after Sept. 11, he says.
Come December, Mr. Innocent will return with his amp - no matter the consequences. "I think it's nonsense," says Innocent, who studied music in his native Paris before enrolling at the Berklee College of Music here. "You can't work without that tool. It's like being a cop without a gun." Today, he takes the afternoon shift on the city-bound platform at Harvard. Though fewer riders crowd his stage, Mr. Innocent and others actually prefer this slot. And down here, the bright light of noon, the chill of dusk, and the dark of midnight are the same. He plugs in his microphone and amp and lines up CDs before starting to sing.
A few commuters clap or drop dollars into his amplifier case as they board the next train. Then, as Innocent sings "Let's Fall in Love," the doors slide shut, the wheels rumble on, and his audience - for now - rolls away.
• Sara B. Miller contributed to this report from Boston.