Two more trends in 20th-century music bear mention. The first is the use of frequently changing meter, first used extensively by Stravinsky, who in his Concerto for Piano and Winds wrote passages where every measure is in a different meter. With this practice, it is debatable if a discernible meter is ever established, and composers often seem to use this tool to evade any sense of meter. On quite the opposite side, another trend is for the use of "additive" time signatures, which appear like this:<br /> <math>\frac{2+3+2}{8}</math> | Two more trends in 20th-century music bear mention. The first is the use of frequently changing meter, first used extensively by Stravinsky, who in his Concerto for Piano and Winds wrote passages where every measure is in a different meter. With this practice, it is debatable if a discernible meter is ever established, and composers often seem to use this tool to evade any sense of meter. On quite the opposite side, another trend is for the use of "additive" time signatures, which appear like this:<br /> <math>\frac{2+3+2}{8}</math> |