Harmony is an important component in music. Chord progressions, which represent harmonic changes of music with understandable notations, have been used in popular music and Jazz. This article explores the question of whether a chord progression can be summarized for music retrieval. Various possibilities for chord progression simplification schemes, N-gram construction schemes, and distance functions are explored. Experiments demonstrate that such profiles can be used for artist grouping and for composition retrieval via top-k queries.