Musical theme in the context of Hoboken-Verzeichnis

In music, the introduction is a passage or section which opens a movement or a separate piece, preceding the theme or lyrics. In popular music, this is often known as the song intro or just the intro. The introduction establishes melodic, harmonic or rhythmic material related to the main body of a piece.

Introductions may consist of an ostinato that is used in the following music, an important chord or progression that establishes the tonality and groove for the following music, or they may be important but disguised or out-of-context motivic or thematic material. As such, the introduction may be the first statement of primary or other important material, may be related to but different from the primary or other important material, or may bear little relation to any other material.

The Super Mario Bros. theme, officially known as the "Ground Theme", is a musical theme originally heard in the first stage of the 1985 Nintendo Entertainment System (NES) video game Super Mario Bros. It was one of six themes composed for the game by Nintendo sound designer Koji Kondo, who found it to be the most difficult track to compose for it.

The theme is set in the key of C major with a tempo of 100 beats per minute and features a swing rhythm with prominent use of syncopation. While the original theme is composed within the sound limitations of the NES's 8-bit hardware, in later installments with more powerful sound hardware, it is often scored as a calypso song led by steel drums. It went on to become the theme of the series, and has been a fixture in most of its titles. It has been reused and remixed in other Nintendo-published games. The theme was included in the American National Recording Registry in 2023 for its cultural significance, becoming the first piece of music from a video game to do so.