One of two:
1) A Quartet
2) A Piano Trio
A numbered musical piece might be called a concerto, an opus, or a composition. It could also be called a symphony.
Study
A four-hand piano piece is a musical composition for two people to play at one keyboard.
nonet
The term "quadruple" in music typically refers to a time signature or rhythmic pattern that divides a measure into four equal beats. It can also describe a composition or section featuring four distinct musical lines or voices. In broader contexts, it may imply a grouping of four elements, such as four instruments or themes, working together harmoniously. Overall, "quadruple" emphasizes the number four in the structure or organization of musical elements.
Psalm.
A numbered musical piece might be called a concerto, an opus, or a composition. It could also be called a symphony.
The term for a second melody that accompanies the main melody in a musical composition is called a "counterpoint."
Study
A four-hand piano piece is a musical composition for two people to play at one keyboard.
instrumental
Fiddle Faddle - musical composition - was created in 1947.
A musical composition, in 8 letters, is a symphony.
A group of Musical Instruments is called a consort.
Basso continuo
I think it is a motive.
A tetrachord in music is a series of four notes that form a scale or a segment of a scale. It contributes to the overall structure of a musical composition by providing a framework for melodies and harmonies, helping to establish the tonality and mood of the piece. Tetrachords can be combined and manipulated to create different musical phrases and motifs, adding depth and complexity to the composition.