The lead sound (for as long as I could stand to listen) was a bright, slightly detuned piano in the upper register, with a fair amount of reverb. The funky wah sound you are hearing is an electric guitar playing a two-note bend.
the bend is 10th fret B string held and 12th fret G string bent up to match the A on the B string, over two beats (more or less), with the wah pedal being pulled back and then dropped in just a little