[Listening extract audio not available in printed QP] The extract is from a trio sonata by Corelli. Two violins play above a figured bass line. (a) How many...

(a) The correct answer is four performers. [1]

Despite the name "trio" sonata, four performers are needed. The three written parts are: two upper melody lines (typically played by two violins) and one bass line. However, the bass line requires two performers to realise it fully, bringing the total to four.

(b) The number differs from what "trio" suggests because the name refers to the number of written parts, not the number of performers. [1]

The "trio" in trio sonata describes the three notated lines: two melody parts and one bass part. However, in Baroque performance practice, the bass part (basso continuo) is shared between two musicians: a bass instrument (such as cello or bass viol) plays the written bass line, and a keyboard instrument (such as harpsichord) realises the figured bass harmonies above it. This means that while only three lines of music are written, four players are required to perform the piece. Arcangelo Corelli was the most influential composer of trio sonatas, and his works established the standard instrumentation and form for the genre.

(c) Two ways the violin parts might interact in a slow movement include any two from the following [2]:

• The violins play in imitation, with one echoing a phrase first heard in the other, creating a polyphonic dialogue
• They play in parallel thirds or sixths, moving together in consonant intervals to produce a warm, blended sonority
• They exchange melodic phrases in a dialogue, taking turns with the main melody while the other provides supporting material
• One violin holds a sustained note (pedal) while the other plays a more decorated and elaborate melody above or below it
• They play sequences where one follows the other at a different pitch level, creating a cascading effect