The student should note the difference between groups 1 and 2
as given above: the terms in group 1 indicate that each
measure, and even each pulse in the measure, is a little
slower than the preceding one, while such terms as _piu lento_
and _meno mosso_ indicate a rate of speed becoming instantly
slower and extending over an entire phrase or passage. Some
composers (_e.g._, Beethoven and Couperin) have evidently had
this same distinction in mind between _rallentando_ and
_ritardando_ on the one hand, and _ritenuto_ and _ritenente_
on the other, considering the former (_rall._ and _rit._) to
indicate a gradually slackening speed, and the latter
(_ritenuto_ and _ritenente_) to indicate a definitely slower
rate. The majority of composers do not however differentiate
between them in this way, and it will therefore hardly be
worth while for the student to try to remember the
distinction.

(_b_) Terms indicating a more rapid tempo.

1. Terms indicating a gradual acceleration.

_Accelerando_, _affrettando_ [Transcriber's Note: Corrected
misspelling "affretando" in original] (this term implies some
degree of excitement also), _stringendo_, _poco a poco
animato_.

2. Terms indicating a tempo which is to become definitely
faster at once.

_Piu allegro_, _piu tosto_, _piu mosso_, _stretto_, _un poco
animato_.

112. After any modification in tempo (either faster or slower) has been
suggested it is usual to indicate a return to the normal rate by some
such expression as _a tempo_ (lit. in time), _a tempo primo_ (lit. in
the first time), _tempo primo_, or _tempo_.

113. _Tempo rubato_ (or _a tempo rubato_) means literally _in robbed
time_, _i.e._, duration taken from one measure or beat and given to
another, but in modern practice the term is quite generally applied to
any irregularity of rhythm or tempo not definitely indicated in the
score.

The terms _ad libitum_, (_ad lib._), _a piacere_, and _a capriccio_,
also indicate a modification of the tempo at the will of the performer.
_Ad libitum_ means at liberty; _a piacere_, at pleasure; and _a
capriccio_, at the caprice (of the performer).

114. The term _tempo giusto_ is the opposite of _tempo rubato_ (and of
the other terms defined in paragraph 113). It means literally _in exact
time_. (_Tempo giusto_ is sometimes translated _quite rapidly_,[2