Alternation
ALTERNA'TION, noun
1. The reciprocal succession of things, in time or place; the act of following and being followed in succession; as, we observe the alternation of day and night, cold and heat, summer and winter.
2. The different changes or alterations of orders, in numbers. Thus, if it is required to know how many changes can be rung on six bells, multiply the numbers 1, 2, 3, 4, 5, 6, continually into one another, and the last product is the number required. This is call permutation.
3. The answer of the congregation speaking alternately with the minister.
4. Alternate performance, in the choral sense.