so i've just been looking at Layla by Eric Clapton, and the notes that ive found in it are A C C# D E F F# G G#
and this doesn't seem to fit a key.
now i know you dont have to stay in key 100% of the time, but im curious, how would i improvise in this song without knowing what key its in?
well the thing is, the key in Layla changes between the verse and the chorus.

from memory i can't remember what they are, but i'm sure there'll be a tab around.

D minor to A major maybe?
yea, i had picked up on the chorus being D minor, but i wasn't to sure about the rest.
so, any tips for what to do when improvising?
Follow the melody? Use some of the existing licks Clapton uses but maybe change the rhythm.