Andre 3000 worked extremely hard to become Jimi Hendrix.  But, a lot of actors have successfully emulated people in history.

However, the producer of All By My Side took it a step further.  Danny Bramson wanted Andre to be believable not just as the "character" but also as the musician.

So, what did the right-handed Andre 3000 do to become believable as one of the best (left handed) guitarists of all time?

Bramson tells Billboard:

"The idea of anyone playing Hendrix, let alone a right-handed guitarist, was one of the greatest challenges of the project. I found a really patient teacher and put together a regimen for Andre when he came out to Los Angeles. He sat in a small studio, six hours a day, putting in dedication (to learn how to play left-handed). His guitarmanship had to carry the idea of grace and fluidity. [Director] John [Singleton] and I declared that we didn't want to have the camera cropped on his face and not the guitar. He kept working in a rehearsal room throughout the production."

The film shows the development of Hendrix in 1966 to 1967.  In the film, Hendrix goes from the a somewhat unknown player in the background to an international rock star.