" All four movements of the last of these pieces have a slow Mesto introduction.
Composer and type of piece required. Elizabeth Sprague Coolidge commissioned the fifth of these pieces, whose Allegro vivace finale is interrupted by two instruments laconically playing the same melody a semitone apart, in A and B-flat. That piece's unpaired central movement is a scherzo featuring a 4-plus-2-plus-3 rhythm marked "alla bulgarese." All four movements of the last of these pieces have a slow Mesto introduction. The fourth of these pieces uses the "arch form" favored by its composer, and its fourth movement makes heavy use of its composer's namesake snap pizzicato. That piece was first performed in 1929 in Budapest. For 10 points, identify these six chamber pieces by the Hungarian composer of Music for Strings, Percussion and Celesta and Concerto for Orchestra.
Composer and type of piece required. Elizabeth Sprague Coolidge commissioned the fifth of these pieces, whose Allegro vivace finale is interrupted by two instruments laconically playing the same melody a semitone apart, in A and B-flat.
string quartets by Béla Bartók [prompt on partial answers] &lt;White&gt;