Born in Spain, Joan Guinjoan studied the piano at the Barcelona Conservatory and then at the Paris Conservatory. He gave his first recital in 1954 in Paris.
In 1961, Joan Guinjoan turned definitively towards composition and studied with Christofor Taltabull, before going on to the Schola Cantorum with Pierre Wissmer and Jean-Étienne Marie at the ORTF for electro-acoustic music. In 1965 he founded the instrumental ensemble «Diabolus in Musica». From then on he undertook important work in promoting contemporary music as conductor of Diabolus in Musica and of various chamber music ensembles and orchestras in Spain and abroad.
In 1981 his book «Ab origine» was published, a synthesis of his musical thought. A year later he received the Reina Sofia composition prize of the Ferrer Salat Foundation, and for the third time, the «Ciutat de Barcelona» prize.
Joan Guinjoan founded and directed in 1988 the Week of International Contemporary Music of Barcelona and in 1989 started work on Gaudi to a libretto by J.M. Carandell, an opera commissioned on the occasion of the Olympic Games in Barcelona. In 1993 Joan Guinjoan founded the Ciutat de Tarragon International Music Composition Competition, and the following year was appointed director of the first International 20th Century Music Festival of Barcelona.
In 1995, Joan Guinjoan was awarded the National Prize for Culture (in the field of music) by the Generalitat of Catalunya. He also became a member of the board of directors of the Society of the Spanish Authors (SGAE).
«The Piano Works of Joan Guinjoan», by the musicologist Rosa Fernández García,was published in 1996 by Editorial Alpuerto.
The world premiere of Self-Párafrasis, took place in 1997 at the International Festival of Music and Dance of Granada and was performed by the Cristofori Quartet.
That same year, a book with an accompanying video cassette entitled «Joan Guinjoan», by M. Rom and J.M. García Ferrer, was published by the Association of Industrial Engineers of Catalunya. In addition, four radio programs featuring his works were aired on Radio Catalunya.
1998 saw the birth of the Joan Guinjoan Quartet at the International Festival of Perelada in Spain. A new book, «Joan Guinjoan», by the writer Xavier García and the composer Augustes Charles, was also published as a coproduction of the Department of Culture of the Generalitat of Catalunya and Editorial Proa