St. Andrew's has had a long history of excellence in its music program. In keeping with St. Andrew’s tradition of liturgical reform, which had included, although against much opposition, the gowning of the choir and the introduction of instrumental music with a melodeon in the services, a 43-stop tracker (mechanical action) organ, built by S.R. Warren, was installed in the rear gallery of the new church (1885). In 1907, a chancel was added at the south end of the church and in it was placed a four-manual Casavant organ with electro-pneumatic action, the pipes being housed in the chambers on either side of the chancel. A similar action was substituted for the original tracker action of the rear gallery organ in order that it also might be played from the chancel console. The chancel organ’s function was to accompany the choir, which had moved from the gallery to its location in the new chancel.
Mechanical problems with the original gallery instrument were on-going through the years and by 1942 it had become unusable, leaving the auxiliary chancel organ to alone support the singing of the congregation. Subsequently progressively increasing maintenance problems with the Casavant organ resulted in a congregational decision, as part of the renewal of the whole fabric of the church, to consider replacing the original Warren instrument and thereby returning the choir to its first location in the rear gallery. In 1983 a free-standing, 50-stop (70 rank) Karl Wilhelm tracker organ replaced the original Warren instrument in the rear gallery.