On
European pressings of
Boy, "An Cat Dubh" runs at a track length of 4:47, and "Into the Heart" runs at 3:28. On
North American pressings of the album, "An Cat Dubh" runs at 6:21, and "Into the Heart" runs at 1:58. This can be easily noted by the visible difference between the two
records. However, the tracks together sound identical on both pressings, and also both have a total run time of 8:14. Early compact disc releases combined the two songs into a single track. Due to the track time differences, it is difficult to make an official determination of where one song begins and where one ends (although the band's digital box set
The Complete U2 and the 2008 remastered version of
Boy standardized the original European pressings' running times). Because of this, the songs are usually considered to be one track. The 1998 single "
Sweetest Thing" features a live performance of both songs from the
War Tour, but only "An Cat Dubh" is listed. ==Composition==