This is an invention of Peter Steele (Type O Negative). Because he always invites friends in the studio and they always help him out with backing vocals. So this group is about 100 people who are all the time different and a credited on every Type O Negative release under the collective name the Bensonhoist Lesbian Choir. All are friends of Peter Steele.
The Bensonhoist Lesbian Choir was really good on Bloody Kisses, but they sucked on October Rust