La Fundación Olivar de Castillejo is a non-profit organization in Madrid that focuses on sustainability and protection of the environment as well as a center for cultural initiatives. This summer they are holding a concert series lasting from June 20th until September 18th. The music performances are range from acoustic and spanish guitar to classical and jazz groups and solo artists.
The concerts are 8€ and start at 20:00. The stage for the series are in a beautiful, tree lined area outside.
The program schedule can be found here.