I saw this group in the early '70s at the Carolina Coliseum in Columbia, SC. They were NOT a rock & roll band.
In its first version, the band was led by "Mahavishnu" John McLaughlin on acoustic and electric guitars, with members Billy Cobham on drums, Rick Laird on bass guitar, Jan Hammer on electric and acoustic piano and synthesizer, and Jerry Goodman on violin.
This group was considered an important pioneer in the jazz fusionmovement. McLaughlin and Cobham met while performing and recording with Miles Davis during the Bitches Brew sessions. McLaughlin was also influenced in his conception of the band by his studies with Indian guru Sri Chinmoy, who encouraged him to take the name "Mahavishnu" which means "Divine compassion, power and justice."
McLaughlin had particular ideas for the instrumentation of the group, in keeping with his highly original concept of genre-blending in composition. He particularly wanted a violinist as an integral contributor to its overall sound. As the group evolved, McLaughlin adopted what became his trademark: a double neck guitar (six-string and twelve-string) which allowed for a great degree of diversity in musical textures, and Hammer became one of the first to play a Mini Moog synthesizer in an ensemble, which enabled him to add more sounds and solo more freely, like the guitar and the violin.
Their musical style was an unprecedented blending of genres: they combined the high-volume electrified rock sound that had been pioneered by Jimi Hendrix (who McLaughlin had jammed with on his initial arrival in New York as part of the Tony Williams Lifetime), complex rhythms in unusual time signatures that reflected McLaughlin's interest in Indian classical music as well as funk, an improvisational concept that was rooted in jazz as well as Indian music, and harmonic influence from European classical music.
There has been a significant resurgence in the popularity of the Mahavishnu Orchestra in recent years, with bands like The Mars Volta naming them as an influence. There have been no less than five major tribute recordings released. In addition, a very comprehensive and critically acclaimed book Power, Passion and Beauty: The Story of the Legendary Mahavishnu Orchestra by Walter Kolosky (AbstractLogix Books) has been published. It contains interviews with all of the band’s members and quotes obtained specifically for the book from many famous admirers such as Jeff Beck, Pat Metheny, the artist Peter Max, Bill Bruford, and many, many more. The Mahavishunu Orchestra have also been sampled in contemporary music, most notably by Massive Attack on their track "Unfinished Sympathy" which sampled "Planetary Citizen" by Mahavishnu Orchestra.(Source: http://en.wikipedia.org/wiki/The_Mahavishnu_Orchestra)