Song is 19, Cameroonian, and a nephew of former Liverpool player Rigobert Song. He became a pro at Bastia last season and made 34 appearances. He's been variously described as a midfielder and a defender, and appears to conform to the "athletic and versatile" Wenger blueprint. He played in midfield in pre-season, but perhaps Wenger has an eye on him as an option in central defence as well. Someone who can cover both positions would be a very canny acquisition at the moment. If he's good enough, of course.

Rupe adds...
The official website, while still not listing Song on their squad pages, confirmed his signing on 17th August with this minute-by-minute account of the 90 minutes he played in the reserves loss to Coventry.