Among the sources that Marsh refers to in his manuscript is ‘Mr Harris’s score’, almost certainly a manuscript score that belonged to James Harris of Salisbury. Although Harris probably had a substantial music collection, little of this survives today, and no known Messiah manuscript can be identified with his ownership. It is not possible to reconstruct the music of the score from Marsh’s annotations, but enough can be known to form a general picture of the contents. These must have represented a version of Messiah that was based on the movements current around 1743, as indeed is true of many other early Messiah sources.
A new factor in the situation is the recent discovery of correspondence
revealing that Harris borrowed Handel’s performing materials for Messiah
between the composer’s London performances in 1743 and 1745, intending
to perform the work at Salisbury. The Matthews score will be re-examined
in the light of the possibility that Harris’s score was copied from, or
amended to conform to, the performing parts that he borrowed from Handel.
If this were the case, the Matthews score might preserve important information
not only about variant settings, but about musical readings that were current
in 1743 (affecting, for example, word-setting), and about instrumentation.