As we get closer to the February 28 release date for Pink Floyd's seven-disc "Immersion Edition" of their legendary 1979 album, 'The Wall,' we're starting to hear a bit more from the set. Three weeks ago we reviewed the demo for 'Young Lust.' Today we learn that 'The Doctor,' the band demo of the song that would become 'Comfortably Numb,' was released to radio.

In this early stage, it could hardly be expected that 'The Doctor' would turn into such a masterpiece. As you would expect from a demo, the arrangement is sparse with rudimentary performances for them to later build upon (although David Gilmour's atmospheric guitar accents are a nice touch).

Roger Waters' lyrics for the verses, sung by Gilmour in another "Huh?" moment, are entirely different apart from "Can you show me where it hurts?" and aren't particularly interesting. Most jarringly, the decision to put in the majestic solo that closes the song hadn't even been made. The song ends after the second verse.

Still, when the 12-string dramatically ushers in the chorus and Gilmour sings "There is no pain," you can't help but feel on more solid ground. If not for him singing "I can't explain, you would not understand" in an American accent, you would think his vocals on the finished product were lifted directly from the demo.

'The Doctor' is a fascinating look inside the origins of one of rock's most famous songs, but should have little interest outside of die-hard Floyd fans and those of us who eat this stuff up. Nearly every decision the band made in the evolution of the song into 'Comfortably Numb' turned out to be the correct one.