These are the audio files for A Whiter Shade of Pale. Download the file for your part, plus the file that is just called A Whiter Shade of Pale, which has all parts.
An MP3 player should recognise the files as being part of an album called MCC July 14 with artist Medina Community Choir.
In terms of instruments used, sopranos are violin, altos church organ, tenor trombone and basses bassoon; the piano part is a piano. The sound is also panned in the stereo field, so sopranos and altos are fully on the left side; tenors and basses fully on the right side.