The Gibb brothers were 8 & 14 when they started singing at the local motor races, between the races, for no fee, folks just threw money. The twins were a wild pair, so it sounds like the bit about them heading for Borstal might be true. Today I heard an interview with the DJ who discovered them - he & the promoter of the races were responsible for their name. Both men had the initials BG, & the DJ referred to himself on air as "BG from (station name)" & taped them & sent the tape of the until then un-named trio to Sydney's top DJ & they were on their way to fame & fortune.

sandra