Yannatos says that effort accounts for much of the high grades.

"It's really difficult to grade someone badly when they've poured a lot of time, a lot of effort and gone to many rehearsals," he says. "If they're very dedicated, they deserve good grades."

While few students outside HRO and musical groups like the HWE know of the classes, Yannatos says the 91r chamber music class has existed at Harvard for at least 25 years.

The class was formerly open to both HRO members and students in other campus musical groups until 93r was formed specifically for HRO members a few years ago to accommodate growing demand and to facilitate grading.

This year, about half of HRO's members are enrolled in 93r, a number Yannatos says is slightly higher than last year. He estimates that half of those taking 93r have taken the class before.

For those still wary about accepting the classes as completely legitimate, Yannatos suggests a trip to Sanders Theatre.

"Anybody who has questions should come to the concerts. They're pretty phenomenal," Yannatos says.