This isn't an "I want to learn how to memorize songs, so how do I do it?" but rather, how do you personally do it. I've head a lot of methods -- singing the melody, learning it on piano so you have the chords and melody in your head, etc. etc. For the past half hour or so I've been working on Nature Boy. I've known the melody for a couple months and play it on DB as a warm-up and as intonation practice (I play it in Dm most of the time, so I play it up by the heel of the [Eb] neck). It's on the setlist for a possible gig (my first one on DB) and I've found that knowing the melody and "playing" it in my head while constructing basslines helps really keep the changes right there in my mind. This is also helping in another way because I'm practicing improvising walking lines (something I'm still inexperienced with.) PS: I'm not sure if this a technique topic, so shuffle it off where it needs to be. I have noticed the DB side is a lot more laid back about this kind of thing, though. I'm still adjusting to the more relaxed DB side of TB, and the fact that technique here isn't just straight physical technique -- "is my wrist position correct?" kind of stuff.