There are a few differences between the U.S. and UK issues on the first disc of this compilation. In the U.S. Harvest Records and its distributor Capitol Records reconstructed their edition from tapes that had been previously altered for the debut 1967 U.S. album Pink Floyd (the original U.S. title for Piper) and other recordings, which were cut from the U.K version. As explained in a note on the back cover of the U.S. edition of A Nice Pair, songs dropped from the U.S. 1967 Pink Floyd album, "Flaming", "Astronomy Domine" and "Bike", are restored for this re-issue.
However, some of the restored songs appear in versions that are different from the U.K. "Piper" release: the eight-minute live Ummagumma recording of "Astronomy Domine" replaces the original four-minute studio recording; "Interstellar Overdrive" fades out slightly early (as it did on the U.S. debut album) and adds a few seconds of silence before "The Gnome", rather than using a segue between these songs as found on the UK version; and "Flaming" is an alternate mix and edit which previously appeared on a U.S. single, and the only track to appear on this album in mono. In later pressings, the correct stereo version of "Flaming" was restored, while the other songs continued to appear in the versions described here. The American version of this album was also released in Canada.