The Portland String Quartet will perform two Tuesday-evening concerts at Colby College in Waterville, one on July 27 and the other on August 3. The 7:30 p.m. performances will be in Lorimer Chapel. Admission is $10 for adults and $8 for students and seniors.

The program for July 27 includes Franz Joseph Haydn's String Quartet in G Minor, Op.74, No.3, "The Rider;" Walter Piston's String Quartet No.2 and Ludwig van Beethoven's String Quartet in C Major, Op.59, No.3, "Hero."

The August 3 concert will feature Beethoven's String Quartet in F Major, Op.18, No.1; Ernest Bloch's String Quartet No.2 and Alexander Borodin's String Quartet No.2 in D Major.

Portland String Quartet members Julia Adams, Stephen Kecskemethy, Ronald Lantz and Paul Ross are conducting their 24th annual summer string quartet workshop. The workshop attracts a select group of musicians from around the world who spend two weeks at Colby in July and August in an intensive schedule of rehearsals, coaching sessions and master classes. The participants' final concert will be at 2:30 p.m. and at 7:30 p.m. on Saturday, August 7, in Lorimer Chapel. Those concerts are open to the public free of charge, as are the institute master classes, held from 4 to 5:30 p.m. on weekdays.

The ensemble, which has played together longer than any U.S. quartet except the Guarneri, was founded in 1969 and currently is celebrating its 29th season without a change in personnel. The quartet has established a reputation for strong performances on its international tours, and its recordings on the Orion, Arabesque and Northeastern labels have won a variety of honors.

For more information call Colby's special programs office at 207-872-3386.