Tempo giusto
In exact, characteristic tempo.
What it means
Tempo giusto means “in exact” or “in the right tempo”. The phrase has two common meanings that cannot always be separated.
The first calls for a strictly maintained beat: after a freely shaped passage, a recitative, or a cadenza, the music returns to a regulated tempo. In this sense the marking resembles a tempo, but additionally emphasizes strictness and excludes rubato.
The second understands giusto as “appropriate” and means that tempo which corresponds to the character of the piece — for a march the march tempo, for a dance the dance tempo. If the phrase stands at the beginning of a movement without further indication, this meaning is usually intended: the composer relies on the genre already providing the tempo.
In the notation
The phrase stands in italics above the staff, either at the beginning of a movement in place of a tempo word or in the middle of the piece after a free section. Occasionally it appears together with a metronome marking, which then makes the intention unambiguous.
Musical use
The marking is used in music whose metre is load-bearing and which therefore tolerates no free shaping: in dance-like movements, in marches, in music with a utilitarian function. It likewise stands after recitative-like or cadenza-like passages, to mark the transition into a regulated beat. In twentieth-century music it is also encountered as a counter-concept to sections with free rhythm.
As tempo ordinario, the term in the seventeenth and early eighteenth centuries carried the idea that every time signature has its own ideal tempo — the larger the note value of the beat, the slower, as described by Friedrich Wilhelm Marpurg (1755) and Johann Kirnberger (1776); from the mid-eighteenth century this convention receded in favor of dedicated tempo words.
Performance practice
Do without rubato and shape instead through dynamics, articulation, and timbre. Count along and check occasionally with the metronome whether you give way at phrase endings — that is where it happens most often. If the phrase stands after a free passage, take the regulated tempo immediately and completely. And if no further marking is there, ask about the genre: it contains the answer that the word presupposes.