Chapman came to Philadelphia where he attended the Curtis Institute of Music from 1964 to 1968, studying organ under Alexander McCurdy who had also been Purvis's teacher.

As one of his first projects, Chapman arranged for the broadcast of Wanamaker concerts which were heard over Philadelphia radio station WUHY (now WHYY-FM) and included his own commentaries about the performances and the organ.

Some pieces, such as an improvisation on "We Gather Together" or an arrangement of "Ding Dong Merrily on High" made reference to other compositions ("All Creatures of Our God and King" and "In Dir ist Freude", respectively here).

He championed the beauty of the symphonic sound of the pipe organ during an era when it was aggressively criticized by the "musically correct" of the period.

Eventually it was discovered that two enthusiasts of the Wanamaker Organ had reproduced digitally remastered recordings of these radio broadcasts of very high quality.

These recordings are of special significance because, shortly after Chapman's death, both the Echo and Ethereal divisions of the organ were damaged in separate accidents and became unplayable for many years.

[10] Chapman and his wife, Sally, were killed when their twin-engine Cessna 310 crashed into the Sangre de Cristo Mountains of the Colorado Rockies while they were returning from a performance in California.

[2][11] The Chapmans were reportedly en route to visit Sally's daughter (from a previous marriage) and new grandchild in Omaha, Nebraska at the time of the crash.