The music hall has a frieze of aegricanes. At the south end of the room is an organ placed between Ionic columns, with top-lighting shedding light into the lobbies behind the columns and to the organ loft. An entrance from the exterior is on the north end of the room, out of view in Gandy's perspectives (drawings 120 and 121).

Drawings 120 and 121 show the music room as built, drawn by Joseph Michael Gandy when he visited the site in 1798. The design of the room slightly varies from that shown in an earlier perspective (drawing 95), omitting the fluted pilasters and with the windows spaced further apart. The middle window on the west wall projects slightly into the room to mirror the facing chimney-piece. A guilloche pattern is omitted on the ceiling.

See SM 14/1/9 for a lecture drawing showing an interior perspective of the music room as in drawing 121.