This month Liebesfreud's "Last Fridays" series of free concerts returns to the Philadelphia Art Alliance. The Liebesfreud Quartet will be joined by violinist Dara Morales (of the Philadelphia Orchestra) and cellist Jesus Morales for a performance of the Brahms Sextet op. 18 in Bb major. Also on the program are two works for string quartet, a Fugue in F minor by Grieg and the delightful Italian Serenade by Hugo Wolf. Friday, May 28, 5:30 pm Philadelphia Art Alliance 251 South 18th Street (southeast corner of Rittenhouse Square)