The Gaylads had never been adequately able to fill the gap left by the departure of Delano Stewart in 1967, for a time BB Seaton and Maurice Edwards recorded as a duo, then they returned to trio form, although they a permanent third member was never found. For "Soul Sister", Ricky Grant added the third voice to the harmonies.
This 1970 single was very much a child of its time, at least in the north where sister power was making its voice heard. But Jamaica was, and remains, a far less liberated culture than the US and UK. Thus, the trio's support for their young sister's independence and their insistence that she "don't let no-one try to rearrange you come what may," was an incredibly strong message to women in this patriarchal society.
Incidentally, Seaton wrote the song with the bass line from Wilson Pickett's classic "In the Midnight Hour" mind, although Jackie Jackson gives it his own flair.
The Gaylads were not renown for taking on concerns beyond the heart, but here they provided a timely message to sisters everywhere.