At Berklee College of Music, a school founded as an incubator of jazz and steeped in the syntax of cool, the pluck of the banjo was once a sound disdained. The bluegrass instrument was considered the stuff of Appalachian Mountains, not urbane Boston.
But what is cool shifts. And next semester, bluegrass will become a sanctioned subject of study at Berklee.
For the first time, the 3,800-student school will permit students to major in mandolin and banjo, the signature instruments of bluegrass. The number of bluegrass ensembles at the school has grown from one to four, and big names in bluegrass, such as Del McCoury, have come to play and teach. Last school year, Berklee bestowed an honorary degree on Earl Scruggs, a noted banjo player.
''We'd had these stealth bluegrass players at Berklee for several years, and the feeling was, 'Let's bring it out in the light of day,' " said Roger Brown, Berklee's president, whose great-grandfather was a fiddler.
Berklee's embrace of bluegrass -- a mix of blues, old time mountain, Celtic, and Scottish music as well as jazz -- places it among just a handful of schools offering formal training in the genre, according to music educators. Most bluegrass programs are located in the South, at schools such as South Plains College in Texas and East Tennessee State University in Tennessee.
Berklee administrators credit interest in bluegrass to a growing appetite among students for a range of musical styles, spurred by the Internet. It also parallels the climbing popularity of the style nationally, with thousands of fans won over by the chart-topping bluegrass soundtrack to the movie ''O Brother, Where Art Thou?" and others wooed by popular bands like String Cheese Incident and the now-defunct Phish.
Also key, some say, was the arrival of Brown, Berklee's third president, in 2004.
Growing up in Georgia, Brown considered bluegrass a vestige of a culture that was best left behind in the post-Civil Rights era. ''I went through a phase where I wanted to reject everything I thought was redneck," he said. ''Bluegrass was part of that."
With time, the stigma associated with bluegrass lessened in his mind. ''Now I am able to appreciate it for what it is," he said.
Bluegrass, a form that was most often learned by ear at picking sessions, is not easily mastered. It demands technical and improvisational skills. It can be difficult to teach bluegrass, which is more free form than some classical styles.
On a recent afternoon, as a Berklee bluegrass ensemble struggled with the standard ''Sittin' On Top of the World," Dave Hollender, the ensemble leader, struggled to explain the problems. The fiddle wasn't coming in on time. The harmony was not in sync. What's more, he said, the music's ethos was missing.
''Tell a story," Hollender instructed one student as she sang. ''Don't read words." Moments later he counseled, ''You have to watch each other's body language."
Thirty minutes passed before Hollender pronounced progress made.
Part of the appeal of bluegrass, students say, is that playing it requires virtuosity.
Jaime Garamella, 25, a guitar player from Danbury, Conn., said: ''because it's so technically demanding, it sits right next to jazz. It's not something that you can just pick up and do."
Berklee's welcome of bluegrass is in some ways at odds with the school's roots. Founded in 1945 as a college for contemporary music, jazz, in particular, the Back Bay school sat apart from the musical establishment. Serious musicians studied classical music, not bebop. It is only recently that jazz has gained traction as a serious subject of study.
But even as Berklee's premier musical focus became more universally accepted, Berklee itself was reluctant to accept other musical genres, including bluegrass.
''The oppressed became the oppressor," said Matthew Glaser, chairman of Berklee's string department, who plays in a bluegrass band.
''People who grew up in an urban environment drew an image in their minds of hillbilly music," Hollender said.
Ron Savage, chairman of the ensemble department at Berklee and a graduate of the school, said, ''For many years, there was the music that was considered acceptable: rock and jazz and classical. Bluegrass was not considered worthy of dedicating a life. It was something that if you failed at the serious things, you did bluegrass."
Simply admitting interest in a musical style like bluegrass could be social suicide.
''It was the kind of music that you didn't talk about, unless you knew someone shared an interest in it," Savage said.
For years, Berklee students found an outlet for bluegrass in the music scene beyond campus, at clubs like the Cantab Lounge in Cambridge, which hosts bluegrass bands and picking sessions every week.
But on a recent afternoon, students flocked to a bluegrass performance on campus. Some 150 of them craned necks in a packed recital room to watch a man with a thick twang and silver pompadour whip through bluegrass songs with his band. In between songs, students peppered Del McCoury, the 66-year-old bluegrass maestro, with questions about his guitar, his band's musical arrangements, and his theories on life and music.
Raucous applause went up after McCoury offered this advice for budding musicians: ''Find what it is you like to do, and stay with it. No matter what it is. If all your friends like the big rock acts, that's fine. It's what's in your heart."