series

Sum of the terms of a sequence. Series may be convergent (the limit of the sum is a finite number) or divergent (the limit is infinite). For example, 1 + 1/2 + 1/4 + 1/8 + ... is a convergent series because the limit of the sum is 2; 1 + 2 + 3 + 4 + ... is a divergent series.

series

In music, the numerical expression of note orders of a tone row, related to a starting pitch of 1. The US composer Milton Babbitt introduced a convention of numbering a series as intervals from zero (unison with the starting note) to a maximum of 11 half-steps or semitones.