Prince is willing to make the ultimate sacrifice on this Purple Rain track, where he declares a religious level of devotion. The enigma that was Prince is embodied in the opening lines:
I'm not a woman I'm not a man I am something that you'll never understand
Prince used his LM-1 drum machine to create the rhythm on this track. Released in 1980, the LM-1 was the first programable unit that used real samples, not synthesized sounds. About 500 were made, sold for $5000 each, which kept them in the hands of serious musicians. By 1984, more advanced machines were on the market, but Prince was still using his LM-1. He had a talent for running the beats through guitar effects and embellishing them with other studio tricks, making him one of the best drum machine programmers of his time.
On the Purple Rain tour, this was a showcase song for Sheila E., who served as Prince's opening act and also joined him on stage. Her live percussion on "I Would Die 4 U" compensated for the beats that couldn't be generated outside of the studio.
Purple Rain served as the soundtrack to the movie of the same name. In the film Prince performs it on stage, wowing the crowd.
Justin Timberlake performed part of this song at the 2018 Super Bowl halftime show in Prince's hometown of Minneapolis, Minnesotta. A projection of Prince ran while a recording of him singing the song was blended with Timberlake.