Abstract-This paper describes a method for obtaining a list of repeated chorus ("hook") sections in compact-disc recordings of popular music. The detection of chorus sections is essential for the computational modeling of music understanding and is useful in various applications, such as automatic chorus-preview/search functions in music listening stations, music browsers, or music retrieval systems. Most previous methods detected as a chorus a repeated section of a given length and had difficulty identifying both ends of a chorus section and dealing with modulations (key changes). By analyzing relationships between various repeated sections, our method, called RefraiD, can detect all the chorus sections in a song and estimate both ends of each section. It can also detect modulated chorus sections by introducing a perceptually motivated acoustic feature and a similarity that enable detection of a repeated chorus section even after modulation. Experimental results with a popular music database showed that this method correctly detected the chorus sections in 80 of 100 songs. This paper also describes an application of our method, a new music-playback interface for trial listening called SmartMusicKIOSK, which enables a listener to directly jump to and listen to the chorus section while viewing a graphical overview of the entire song structure. The results of implementing this application have demonstrated its usefulness.