“I must have played this song at least six or seven hundred times,” said Jaime Baptiste, 23, a drummer and one of several alumni who return each year for the New York City Marathon . As runners raced past the band at Lafayette and Clermont Avenues in Fort Greene, Brooklyn, their focused grimaces melted into cheek-splitting smiles. Those furiously pumping their arms slowed long enough to wave.

More than 100 bands, with nearly 800 performers, took to the city’s streets yesterday in support of the runners and thousands of fans who lined the marathon course. From bagpipers to rappers to hard rockers, the soundtrack of yesterday’s race was something more apt for a music festival than a marathon. With three to four musical acts per mile, the performers were spread over distance rather than time, turning 26.2 miles of city pavement into one gigantic, eclectic stage.

According to race organizers, the growth of the musical aspect of the event evolved rather organically, from the neighborhoods the race is run through. “When we took the marathon to the streets in the mid-’70s, over the years local bands would just show up on the sidewalks, picking their own spots,” said Arnold Sitruk, the coordinating producer for the marathon.

“They would play to cheer the runners on, and that steadily grew.” But as the marathon grew into the mega-event it is today, the mass of musicians began creating logistical headaches. So the New York Road Runners Club created an application process for the bands and secured city permits for performers. (Most are volunteers.) Just before Mile Marker 4 in Bay Ridge, Brooklyn, yesterday, the Clann Eireann bagpipers wailed as the first of the women’s elite runners hustled past.