Farrell was the bandleader of Alternative/Metal bands Jane's Addiction and Porno for Pyros. In 1991, prior to Jane's Addiction dissolving, he. his bandmates, Ted Gardener and Marc Geiger created the Lollapalooza festival as a farewell tour.
In 2001, he put out a solo album, Song Yet To Be Sung, whose lyrics are much inspired by Jewish mysticism.
Farrell restarted Jane's Addiction and Lollapalooza in 2003.