With no surviving autograph score of this Offertory motet, the duet Sub tuum praesidium
, K198 in a variety of manuscript copies has provided scholars over the years with much scope for discussion. The first topic for many years was the identity of the composer: that has now been firmly established as being Mozart himself. The second line of enquiry has been whether the work should be performed by soprano and tenor (which would be an unusual vocal combination in Mozart’s sacred music) or by two sopranos. That line has finally moved towards the soprano duet recorded here. Another question which has concerned scholars has been whether this was originally a work for the opera house, adapted for the church, or whether it was intended from the outset as a sacred work. But all that detective work is in the end secondary, for here is a glorious Mozartian duet in his lyrical key of F major for two equal sopranos and string accompaniment. Mozart especially relishes the pairing of the evenly matched voices.
from notes by Robert King © 2006