allegretto—moderately quick tempo. slower than allegro but faster than andante
allegro [I]—fast, lively tempo. From the Italian word for cheerful or gay.
andantino—faster than andante, slower than allegretto. Sometimes andantino is interpreted as the opposite: slower than andante
chamber music, Kammermusik [G], musique de chambre [F], musica da camera [I], musica cameralis [L]—"Classical Music" for a small ensemble, generally 8 or fewer players with a canonical emphasis on 3-6 players. explore
moderato [I], moderamente, modéré [F], modérément [F]—moderately, at a moderate tempo, applying a touch of restraint to its related word(s), e.g. allegro moderato
opus [L], opera[pl], Op., Opp, WoO, Op. posth—work, as in a work of art. For unique identification, publishers/composers often assign an "opus number", abbreviated as "Op." (e.g. Op. 1). A range of works by opus number, uses the plural "opp." (e.g. "Opp. 1-3"). A single opus number may refer to a collection of works (e.g. a set of quartets) giving rise to designations like "Op. 1, No. 4". For misc. works without opus numbers, "WoO" is often used (e.g."Without Opus"). Posthumously assigned numbers may use "Op. posth". Opus numbers may not precisely reflect chronology (publication vs. composition), can be erroneous, sparse or duplicative. Thus, the works of some historically important composers may use separate catalog numbers (e.g. Bach, Haydn, Schubert). See wiki
poco, un poco, poco a poco—a little bit, e.g. "andante un poco moto" is andante with a little more motion than typical. "poco a poco" means a little bit at a time, gradually.
string trio, Streichtrio [G], Trio d'archi [I], Trio de cordes [F], Trío de cuerdas [S]
—a work for three stringed instruments, most commonly violin, viola and cello. A more rarefied form than the string quartet perhaps because the texture is sparse (each instrument highly exposed) and the means more difficult for natural harmonic richness. But these become challenges and assets in the great trios. Trios almost always emphasize countrapuntal writing with each of the three players in strong relief.