Today we talked about Absolute Pitch (AP) in Psychology of Music. I had one of my theory students -- who is an AP possessor -- come in so the students could ask him questions during the discussion. In the spectrum of AP possession, this student is not at the extremely far end, so he can and does utilize relative pitch (RP) from time to time. Thus he was able to explain some of the differences between perceiving music through AP and through RP. Strict AP perception places each separate musical note into a category, ignoring any contextual identity such as being part of a chord or being the tonic note of the key. Thus this type of perception is very pointillistic, creating a picture of music not unlike a George Seurat painting. What I don't know (not being a strict AP possessor) is if, like a Seurat painting, the separate notes do meld together into a cohesive whole for an APer. It seems that any such melding would be a switch to an RP perspective. Thus any appreciation for the gestalt of a musical piece would necessitate some ability for relative pitch.
Some of my students wished they had AP, but this was primarily so they could do better on melodic dictations in the classroom. For the most part, AP does not help the musician, beyond creating an internal pitch pipe. Any AP possessors out there that want to offer their perspective (heh)?