ATLANTA — Since April, André 3000 has been on the road, traveling from festival to festival with his old partner Big Boi to celebrate the 20th anniversary of their debut album as Outkast. And on Sept. 26, he’ll star, under his original name, André Benjamin, as Jimi Hendrix in “Jimi: All Is by My Side,” a biopic about the year just before Hendrix’s breakthrough, when he moved to London, underwent a style transformation and squared off against Eric Clapton.

Don’t let those things fool you. Over the eight years since the last Outkast project, the Prohibition-era film and album “Idlewild,” André 3000, now 39, has become, through some combination of happenstance and reluctance, one of the most reclusive figures in modern pop, verging on the chimerical.

Invisible but for his fingerprints, that is. For the better part of his career, André 3000 has been a pioneer, sometimes to his detriment. Outkast was a titan of Southern hip-hop when it was still being maligned by coastal rap purists. On the 2003 double album “Speakerboxxx/The Love Below,” which has been certified 11 times platinum, he effectively abandoned rapping altogether in favor of tender singing, long before melody had become hip-hop’s coin of the realm. His forays into fashion (Benjamin Bixby) and animated television (“Class of 3000”) would have made far more sense — and had a far bigger impact — a couple years down the line. In many ways, André 3000 anticipated the sound and shape of modern hip-hop ambition.