The wild service tree, Sorbus torminalis, has its own song. Le bois d’alisier (The wild service tree wood) is a folk number from Évelyne Girardon (=Évelyne Beline). It is based on a traditional French song called Voici La Saint Jean (Midsummer – St John’s Day - is here) and is very widely known both in France and elsewhere. The festival of St. John is on 24th June and this is sometimes considered as midsummer. Both 24th June and 23rd June, St. John’s Eve, are associated with various pagan activities such as bonfires and have roots in the pre-Christian past. There appears to be some uncertainty as to the original home of the song, but claims have been made for Jumièges in Upper Normandy, Switzerland and elsewhere. The song has also been exported to North America.
The original Voici La Saint Jean song has no reference to a wild service tree wood or anything like it, so this would seem to be a late addition from Évelyne Girardon or another.
The song can be listened to here: http://www.myspace.com/evelynebeline/music/songs/le-bois-d-alisier-36648310
The reference to the wild service is in the chorus: Vole vole mon coeur au bois d’alisier, vole vole mon coeur (Fly, fly my heart to the wild service tree wood, fly, fly my heart).