The character of Winslow Elliott is a parody of Canadian pianist Glenn Gould. Elliott's eccentricities - his gloves, bulky layers of clothing, and aversion to touching people - are based on Gould's hypochondria and his hatred of cold (especially when playing). Gould was also known for unconsciously humming/vocalizing music even when recording, similar to Elliott's vocalizations while under his therapist's hypnosis. Elliott's conversation with Rodrigo about preferring Bach to Mozart is also true to Gould, who revered Bach and criticized Mozart (and most Romantic-era composers) for his "hedonistic" music. In fact, the most un-Gouldian element in the episode is Elliott's association with Rachmaninoff -- considered the most Romantic and virtuosic of pianist-composers; Gould never recorded Rachmaninoff's piano concertos, unlike Elliott.
The tune that Rodrigo and Winslow play at the organ is Bach's Toccata and Fugue in D minor, the most recognizable melody in the organ repertoire. It is associated with horror and Gothic genres, partly because of its inclusion in the Phantom of the Opera (1962) film. Incidentally, the pianist that Winslow's character is based on (Glenn Gould) made only one organ recording, also of a Bach piece, The Art of Fugue.