To fully understand music being played, the student must learn the basics of the underlying music theory. Along with musical notation, students learn rhythmic techniques like controlling tempo, recognizing time signatures, and the theory of harmony, including chords and key signatures. In addition to basic theory, a good teacher stresses musicality, or how to make the music sound good. This includes how to create good, pleasing tone, how to do musical phrasing, and how to use dynamics (loudness and softness) to make the piece or song more expressive.
Most music lessons include some instruction in the history of the type of music that the student is learning. When a student is taking Western classical music lessons, music teachers often spend some time explaining the different eras of western classical music, such as the Baroque Era, the Classical era, the Romantic Era, and the contemporary classical music era, because each era is associated with different styles of music and different performance practice techniques. Instrumental music from the Baroque era is often played in the 2000s as teaching pieces for piano students, string instrument players, and wind instrument players. If students just try to play these Baroque pieces by reading the notes from the score, they might not get the right type of interpretation. However, once a student learns that most Baroque instrumental music was associated with dances, such as the gavotte and the sarabande, and keyboard music from the Baroque era was played on the harpsichord or the pipe organ, a modern-day student is better able to understand how the piece should be played. If, for example, a cello player is assigned a gavotte that was originally written for harpsichord, this gives the student insight in how to play the piece. Since it is a dance, it should have a regular, clear pulse, rather than a Romantic era-style shifting tempo rubato. As well, since it was originally written for the harpsichord, a light-sounding keyboard instrument in which the strings are plucked with quills, this suggests that the notes should be played relatively lightly, and with spaces between each note, rather than in a full-bodied, sustained legato.