Celtic music has replaced Doo Wop on PBS as its most popular music programming for the Pledge Drives.  Is classical music making a comeback?  A new video from a Southern California classic trio shows why it just might be on track to grow in popularity.  Live unplugged performance of the 13th century song "Madre de deus" ('Mother Of God") from the Cantigas de Santa Maria (No. 422) commissioned by King Alphonso El Sabio of Spain, sung in Galacian-Portuguese.