It is Andy and Andy also multitracked the oohs on the bridge and the middle "ba-ba-ba" harmonies since he was the better singer of the two :) and so experienced in harmony via his earlier act with his brothers. Interesting aside on this track- Bruce Botnick engineered this session... five weeks after recording the Doors first album including "Light My Fire". And two weeks after tracking "Bluebird" by Buffalo Springfield. Bruce was on a roll as an engineer during the summer of love.
A beautifully textured soft-rock gem. Who is shadow/singing with Claudine? There is an alternate version on which her then-husband Andy Williams shadow/sings behind her. Here, it sounds like it might have been producer/arranger Nick DeCaro.