Janet Maguire, born in Chicago, raised in New Rochelle, New York, began musical studiies at the age of six, took a BA degree with a major in piano at Colorado College, then went to Paris to study composition with René Leibowitz, writing several works in the 12-tone technique.  Several summers at the Darmstadt Ferienkurse introduced her to new, freer tendencies of composition, such as the music of Gyorgy Ligeti, Luigi Nono, Karlheinz Stockhausen, among others, and encounters with Iannis Xenakis in Paris considerably widened the horizon of sound for her.

A constant search for deepening and widening her sound world has resulted, as shown in the variety of some 50 compositions written since, for diverse instrumental and vocal combinations, orchestral, chamber, choral, soloistic works and opera.

An orchestration of selections of Offenbach's music entitled "Nuits Parisiennes" (Bote & Bock), the book on orchestration, "Thinking for Orchestra" (G. Schirmer, Inc) in collaboration with Leibowitz, and the Finale of Puccini's "Turandot" which she wrote from Puccini's own notes, all point to a decided inclination toward the composite sound, a massive sound universe.

Maguire was awarded residence at Copland House by the Aaron Copland Foundation in 2006.  She worked as music critic for the International Herald Tribune in Paris.  She is currently president of the association "Musica in Divenire" in Venice, organising concerts of new music and inviting other composers.  She is a member of the European Society for Culture.  The John Simon Guggenheim Memorial Foundation awarded her a Fellowship in 2008.  Her works are heard in many countries.