Guarneri String Quartet second violinist John Dalley, 73, has been diagnosed with prostate cancer and will undergo radiation treatment January 15, says the group’s manager Mary Lynn Fixler, vice president of Herbert Barrett Management. The Guarneris, who are wrapping up their 45th and final season, will continue their schedule while Dalley treats his condition with hormones until January 13. Dalley will then receive radiation treatment five times a week, for four to six weeks. The group plans to resume its farewell tour in the spring and will make up for the missed dates at the start of the 2009–10 season, Fixler says.

In an e-mail to Strings, Guarneri first violinist Arnold Steinhardt commented about Dalley’s illness and the ensemble’s morale. “From the outside you would never know anyone in the Guarneri [String Quartet] is sick,” Steinhard wrote. “We are performing almost every night and having a wonderful time at it. [Dalley] is sounding his usual artful self and we are all savoring this last season of ours with great pleasure and deep gratitude for what the music profession has given us.”

Fixler confirmed that Dalley is in a good state of mind, and that he just feels bad that his illness upsets the group’s final season.

Dalley formed the quartet in 1964 with Steinhardt, violist Michael Tree, and cellist David Soyer, who was succeeded in 2001 by Peter Wiley. In 2007, the Guarneris announced they would be splitting up at the end of the 2008–09 season. Strings spoke with Steinhardt about the decision in the October 2007 issue. “We would like to go out sounding the way people expect us to sound and the way we expect ourselves to sound,” Steinhardt says in the article.

The quartet will be featured again in Strings in February.

Born in Madison, Wisconsin, Dalley studied under Efrem Zimbalist and taught at Oberlin Conservatory. He was a member of the Oberlin String Quartet and served as artist-in-residence at the University of Illinois. He also played at the Marlboro Festival, where the Guarneris had their debut. These days, he teaches at the University of Maryland, and plays an 1810 Nicholas Lupot violin.