Friendly discourse is the pattern of the relationship between the two violins in the Trio Sonata in B flat, written in 1754. The upper instruments either alternate in amicable dialogue or move together in parallel thirds and sixths. The quick changes of mood which are characteristic of the keyboard sonatas are less in evidence here. The muted main theme of the slow movement makes one wonder whether Mozart knew it. The pizzicato theme derives from the bass part, which is thematically more integrated with the violin parts than in the other movements. In the last movement, the violin writing is more imitative in texture.
from notes by Clifford Bartlett © 1988