0 a group of four people who play musical instruments or sing as a group -- 四重奏樂團；四重唱組合
1 a piece of music written for four people -- 四重奏（曲）；四重唱（曲）
He has composed 18 quartets and 14 symphonies. 他譜寫了18首四重奏和14首交響樂。
In the quartets, the allusions are more subtle, and f ulf il a different purpose, creating a complex network of cross-references.
When these trials are removed, children select novel kinds from pairs as often when these are tested after quartets (0n76) as before (0n76).
Unfamiliar kinds were also selected more often from pairs (0n55) than from quartets (0n22).
Subjects were assigned to one of four conditions, defined by feedback (name training versus mild acceptance) and test set order (pairs first versus quartets first).
The unfamiliar and familiar pictures were randomly assigned to either quartets or pairs with the constraint that only one unfamiliar appear in any test set.
Equal numbers of boys and girls were assigned to two test orders, pairs first and quartets first.
Since double categories are 2-fold categories, this means that we need to define the 4-fold category of horizontal quartets of vertical quartets.
Responses between quartets may thus echo and proliferate.
