Terry Riley and Stefano Scodanibbio The Dark Queen Mantra Del Sol String Quartet; Gyan Riley, guitar Sono Luminus   On this Sono Luminus CD, Terry Riley’s chamber works are superlatively performed by Del Sol String Quartet. Joined on the title piece by the composer’s son, guitarist Gyan Riley, the group navigates an array of rhythms, many of Spanish origin. Movement titles evoke the Basque region Vizcaino and the paintings of Goya. The final, eponymous, movement builds to an intense conclusion; Gyan Riley incorporates distortion and high volume, matching the whirling dance of the quartet in a rock-inflected finale.