Dominoes spots from one to six are generally arranged as they are on six-sided dice, but because blank ends having no spots are used, seven faces are possible, allowing 28 unique pieces in a double-six set. However, this is a relatively small number especially when playing with more than four people, so many domino sets are "extended" by introducing ends with greater numbers of spots, which increases the number of unique combinations of ends and thus of pieces. Each progressively larger set increases the maximum number of pips on an end by three, so the common extended sets are double-nine, double-12,
Les Double Six again to a second track, "doubling" each individual vocal part. Singing in French, they performed jazz standards, particularly themes by Quincy Jones and Dizzy Gillespie, adding the poetic or humorous lyrics written by the imaginative Perrin. Inspired by several American groups, the singers vocalized in the manner of instruments, reconstructing brilliant improvisations of saxophones, trumpets or trombones. The group was not long-lasting. Because of Perrin's health problems (she had contracted tuberculosis in 1949), Les Double Six dissolved in 1966. They recorded four albums between 1959 and 1964. Many members of the group went on to join the Swingle Singers, which