Emily Barker is an Australian singer-songwriter; The Red Clay Halo are a multi-instrumental trio. Together they are Emily Barker & The Red Clay Halo, and their song Nostalgia, from the album “Despite The Snow” featured as the title track to the UK version of Wallander.
Wallander has a very distinctive ringtone – generally heard just before he is informed of yet another murder – which I managed to track down a link to in this Pistonheads post.
Image courtesy of Emily Barker’s Website.