Rock 'n' roll developed in the mid-twentieth century as a combination of other genres, such as blues, country, and jazz. Despite its eclectic origins, the music was usually stripped down, featuring limited combos. The typical instrumentation of a rock combo is one or more guitars, electric bass, drums, and occasionally a piano, organ, or horns.

Rock 'n' roll developed in the mid-twentieth century as a combination of other genres, such as blues, country, and jazz. Despite its eclectic origins, the music was usually stripped down, featuring limited combos. The typical instrumentation of a rock combo is one or more guitars, electric bass, drums, and occasionally a piano, organ, or horns.

The time signature is two numbers, which are stacked one on top of the other and are placed at the beginning of a piece of music. The top number indicates how many beats are in each measure. The bottom number indicates how long each beat will last, with a four meaning a quarter more, and an eight an eighth note.

The eighty-eight notes on a keyboard are produced by pressing white and black keys. The black keys are positioned slightly higher and farther back, as they hold all of the sharp and flat notes on the twelve-tone chromatic scale. This arrangement allows the natural notes to be played more easily, and make the non-natural notes more obvious.

The eighty-eight notes on a keyboard are produced by pressing white and black keys. The black keys are positioned slightly higher and farther back, as they hold all of the sharp and flat notes on the twelve-tone chromatic scale. This arrangement allows the natural notes to be played more easily, and make the non-natural notes more obvious.

The time signature is two numbers, which are stacked one on top of the other and are placed at the beginning of a piece of music. The top number indicates how many beats are in each measure. The bottom number indicates how long each beat will last, with a four meaning a quarter more, and an eight an eighth note.

In musical notation, the note "piano" above a clef indicates that the music should be played softly. Often such a mark, sometimes abbreviated with just a "p," will come in the middle of a piece to indicate a change of volume. The opposite notation is "forte," which indicates that the music should be played loudly.

In musical notation, the note "piano" above a clef indicates that the music should be played softly. Often such a mark, sometimes abbreviated with just a "p," will come in the middle of a piece to indicate a change of volume. The opposite notation is "forte," which indicates that the music should be played loudly.

Although configured and played quite differently, both the accordion and the harmonica produce sound by having air blow over free reeds. While the accordion has buttons to open and close specific reeds, a harmonica player blows over a specific hole to create the desired tone.

Although configured and played quite differently, both the accordion and the harmonica produce sound by having air blow over free reeds. While the accordion has buttons to open and close specific reeds, a harmonica player blows over a specific hole to create the desired tone.