They provided the 'angel on your shoulder' in the lyrics of rock band Glasvegas' hit single Geraldine.

However, nothing could have prepared the 'angels' for what came next.

The band played a surprise gig at the Scottish Association of Social Work's (SASW) annual awards at Edinburgh's Assembly Rooms.

Cousins James and Rab Allan performed an acoustic set of four songs before posing for photographs and mingling with guests.

They have been darlings of the profession ever since recording the 2008 song in praise of a social worker. The paean to the profession was among those played during the awards after the musicians stepped in when the previous entertainment for Monday's event fell through.

The band members, a sound engineer and the band's manager all came along to the awards after SASW manager Trisha Hall sent a desperate email via the 'contact us' button on the Glasvegas Website.

Ms Hall said: "When the response came and suggested James, the singer and Rab, lead guitarist would consider coming along I couldn't believe it.

"I was blown away by their willingness to come and play for us, and give social work in Scotland, and the people nominated for the awards this kind of fantastic support and exposure. I simply can't thank them enough for responding in this way."