Students seem to anticipate the end of the lectures, when Perry pulls out his guitar and sings one of his songs on a lecture topic. He provides the lyrics and mp3 files to students so they can follow along.

"It's fun for the students and fun for the professor as well," Perry says. "I enjoy seeing people perk up, doing something other than hours of lectures."

The soft-spoken Perry began writing songs about neuropathology as a resident at the University of Texas-Southwestern Medical School, when an attending physician at a conference jokingly challenged the residents to be more entertaining. Perry took it to heart and wrote his first song, "Schwannoma," about the peripheral nerve tumor. By the end of his song, Perry had attracted two or three times more people into the room from those passing by who wanted to listen.

"Later on, when I began teaching medical students, I found the songs to be a useful tool for people with better musical memories than rote memories," Perry says. "There are a lot of good musicians in medicine."

When writing songs on neuropathology, Perry works to find several pieces that might fit the rhythm of the topic. "It's a challenge to get the longer medical terms to fit into a preexisting format," he says.

That rings true in the "Pituitary Adenoma" song, sung to the tune of "Danny's Song," recorded by Kenny Loggins in the 1970s:

"Patient presents to you with bitemporal hemianopsia

Prolonged amenorrhea, and galactorrhea

MR imaging reveals a sellar neoplasm, pushing up the optic chiasm,

From prolactin forming cytoplasm

Pituitary adenoma, with your disrupted reticulin stroma

You've lost the microacinar pattern of the normal gland

Your cells appear so monomorphic, with nuclei so round and perfect

And salt and pepper nuclear chromatin... "

Perry, who has won several teaching awards — including the distinguished service teaching award from three classes and the professor of the year award from the Class of 2007 — says many of the songs he uses were popular before most of his students were born, which presents more of a challenge every year as students get younger. "But I hope that they enjoy it enough to look up the original," he says.

Robert E. Schmidt, M.D., Ph.D., professor of pathology and immunology and director of the division of neuropathology at the School of Medicine, said he was surprised at first that Perry's students had taken to the end-of-lecture songs.

However, he was soon convinced by the warm reception of Perry's songs by normally intensely focused medical students.

One year, students even held up lighters, a typical rock concert gesture calling for an encore, during one of Perry's songs, Schmidt said.

Perry's musical background comes from taking folk guitar lessons while growing up. He also was the lead singer in a rock band in high school, in which he sang songs by The Who, Journey, Rush, The Beatles and ZZ Top. He also sang in the school choir and started taking voice lessons at that time, subsequently spending more of his efforts on classical music.

Perry and his wife, Zenobia, also a musician, sang their vows to each other at their 1990 wedding, which featured mostly original music.

These days, Perry also sings professionally as associate principal tenor for the American Kantorei and its Bach at the Sem series at Concordia Seminary in Clayton. He also sings solos with other St. Louis choirs or at weddings occasionally.

"I get more nervous at other peoples" weddings than I did at my own," Perry says.

Zenobia Perry is the pianist at a local church and has recorded a CD of original music.