A minor seventh is a musical interval that spans seven diatonic scale degrees and consists of a minor third and a perfect fifth. In terms of semitones, it is made up of ten half steps. For example, if you start on the note C, the minor seventh above it would be B♭. In chord construction, a minor seventh chord includes a root note, a minor third, a perfect fifth, and a minor seventh. For instance, the C minor seventh chord consists of the notes C, E♭, G, and B♭. This chord is commonly used in various music genres, adding a rich, complex sound.