Meno mosso
“Less moved” — slower from here than before.
What it means
Meno mosso means “less moved” and calls for playing more slowly from the marked point than before. The marking names no absolute tempo but sets the new one in relation to the old. How great the difference should be remains open; in practice a clear but not dramatic pulling back is meant.
Decisive is that the change happens abruptly. Herein lies the distinction from ritardando, rallentando, and lentando, which all call for a gradual slowing down. Meno mosso, by contrast, sets a new tempo that applies from the first note. Related is ritenuto, which likewise means an immediate pulling back but designates rather a holding back within a phrase than the tempo of a whole section.
Its counterpart is più mosso.
In the notation
The phrase stands in italics above the staff at the point from which it applies, and remains in effect until a new tempo marking or the end of the section. Some editions add a metronome number, which then often comes from the editor. After the section, a tempo or tempo primo restores the earlier tempo.
Musical use
The marking usually marks a new formal part: the secondary theme of a movement, the middle section of a three-part piece, a calm episode within a moving course. It creates contrast without giving up coherence, because the new tempo remains related to the old. In the music of the nineteenth century, in which tempo is handled freely as a means of shaping, it is especially frequent.
Performance practice
Take the new tempo immediately and completely, without transition — a creeping slowdown turns the marking into a ritardando. Decide beforehand how much slower you will go, and check whether the new tempo fits the movement of the section. In ensemble the first bar is decisive: whoever still wavers there carries everyone else along. And remember the starting tempo, for at a tempo you must find your way back to it.