American Classics
- Organization devoted to exploring the history of American popular music. Site includes concert schedule, programs and audio selections from past performances, and online ticket sales.
- http://www.amclass.org/

Spectrum Singers
- Performing choral music from the pre-Renaissance through the 20th century, emphasizing seldom-heard works by master composers. Concerts, tickets, auditions, rehearsals, archives.
- http://www.spectrumsingers.org/

Ryles Jazz Orchestra
- The house big band at Ryles Jazz Club, directed by Frank Vardaros. Site includes concert schedule.
- http://www.rylesjazzorchestra.com/

Musica Sacra
- Small choral ensemble formed in 1959. Site includes performance schedule, ticket purchase, list of musicians, and e-mail list.
- http://www.musicasacra.org/

Hi-n-Dry
- Recording studio founded by the late Mark Sandman, frontman of the band Morphine. Includes CDs, MP3 downloads, and links to sites of its artist roster, as well as tour dates.
- http://www.hi-n-dry.com/

Shimamoto Sound
- A recording studio with digital and analog equipment offering a full range of services. Features lists of equipment, rates and photos of facilities.
- http://www.shimamotosound.com

Cambridge Society for Early Music
- Presenting performances of solo, chamber, choral, and orchestral music from the Middle Ages through the early 19th century. Site includes concert schedule, group history, awards, and early music links.
- http://www.csem.org/

Liber unUsualis
- Vocal trio performing medieval and early Renaissance music. Site includes concert information, individual bios, and sound samples.
- http://www.liberunusualis.com/

New School of Music
- Non-profit community organization providing music instruction to adults and children. Extensive site includes course listings, program descriptions, news, and directions and map.
- http://www.cambridgemusic.org/

Radius Ensemble
- Chamber ensemble performing contemporary music.
- http://radiusensemble.org/

Cambridge Community Chorus
- Amateur group reflecting the broad diversity of racial backgrounds, ages, religions, and political philosophies that comprise the city of Cambridge.
- http://cambridgechorus.org/

The Double Deckers
- Cambridge-based ska band with influences of ska, pop, rock, funk, and swing.
- http://www.thedoubledeckers.com/

Sam Davis Guitar World
- Offering private guitar lessons in jazz, blues, rock, folk and funk for beginners through professionals.
- http://www.samdavis.com/

MIT Concert Band
- Performing original works for winds since 1948; site includes concert and rehearsal schedule.
- http://web.mit.edu/bavicchi/www/

Cambridge Symphony Orchestra
- Adult amateur musicians dedicated to performing good music at free concerts in and around Cambridge. Site includes concert schedule and directions.
- http://www.cambridgesymphony.org/

Cambridge Madrigal Singers
- Cambridge-based ensemble performing a cappella and accompanied works from all musical periods.
- http://www.cambridgemadrigals.org/

Cambridge Folk Orchestra
- Offering music for international folk dancing and weddings.
- http://ftp-swiss.ai.mit.edu/~jaffer/CFO.html

World Music
- Concerts from around the world, presented at Sanders Theater, the Somerville Theater, and other venues. [Requires frames]
- http://www.worldmusic.org/