Perle’s serenades also reference more distant models. He was, he explained, gesturing at “the way in which the word ‘serenade’ was used in the eighteenth cen- tury,” as “something between chamber music and symphonic music”—hence the scale of instrumental forces, namely, eleven players in each serenade. (The exact configuration of instruments differs from one to the next, though.) From this vantage, the scores’ emphasis on wind instruments accords well with the en plein air heritage of the classical serenade. Likewise, Perle underlined the structural flexibility afforded by the genre (Mozart’s have anywhere from three to eight movements, for example). Perle took advantage of this license to explore the same distinctive layout in all three works—a symmetrical, five-movement “arch” form closely associated with Bartók.