These are the audio files for Jesus Child. Download the file for your part, plus the file that is just called Jesus Child, which has all parts.
An MP3 player should recognise the files as being part of an album called MCC Christmas 13 with artist Medina Community Choir.
In terms of instruments used, sopranos are violin, altos woodblock, tenor trumpet and basses bassoon; the piano part is a piano. The sound is also panned in the stereo field, so sopranos and tenors are fully on the left side; altos and basses fully on the right side.