David GraySinger-songwriter crooners David Gray and Ray LaMontagne just added a Seattle (almost) date to their tour this summer. UK’s Gray brings his downtempo textured pop and LaMontagne his stripped-down folk to Marymoor Park on September 12, currently the last date on their national tour together.Tickets go on sale Friday at 10 a.m. (presale on Thursday) at livenation.com, for $37.50 and $69.50.Ray LaMontagne