The Cameron Crowe / T-Bone Burnett documentary chronicling the critically acclaimed 2010 musical collaboration between Elton John and Leon Russell debuts tonight on HBO.

In "The Union" (9 p.m. ET), Crowe ("Jerry Maguire," "Almost Famous," "Pearl Jam Twenty") shows a candid Elton John during his composing process, something never filmed before.

Filming for "The Union" began in 2009, covering the entire writing and recording process of John's album with Russell.

Sounds good to me. Check out a clip of an interview with Elton John below.

If you were planning to brave Thursday night's predicted Winter Weather Event to see the iconic '70s singer/pianist Leon Russell at Raleigh's Lincoln Theatre, you can leave your coat in the closet. The show has been postponed to April 18. There's been no reason given, but tickets for tonight's date will be honored -- or you can get a refund at point of purchase.