the new theme has the effect of an interjection —a kind of caesura—temporarily halting the flow of semiquavers, which resumes immediately afterwards with cascading scales over the fugue subject in the bass line. after a reprise with the parts inverted between violin and harpsichord, the middle section continues with joyful dance-like material drawn from the ritornello in half-bar exchanges between the violin and upper harpsichord before a cadence in e minor. the eight bar opening segment of section "b" is then reprised with the parts inverted followed by another episode of one-bar exchanges of motifs from the ritornello between all three parts until the music comes to a halt with a cadence in b minor. it resumes as a fugue on the counter-subject of the ritornello but the flow of the counter-theme is interrupted four times by half-bar interjections of the "b" theme.