Watch the David Gilmour online guitar lesson by Jeff McErlain from Kings of Tone
Most of David Gilmour's solos are composed. So it does make me feel better to know that he didn't make up the solo to "Comfortably Numb" off the top of his head! He says that he will lay down a number of solos in the studio and piece the best parts together and then learn it. I have often used this approach and it works quite well. His solos are as much a part of the song as the melody and lyrics, can you imagine "Comfortably Numb" without those solos? Me neither. So while you are at it why don't you learn that first solo in "Comfortably Numb"? You will be glad you did.