‡a 1 v. (various paginations) : ‡bill., maps ; ‡c 28 cm.
‡a 1 sound disc (57 min.) : ‡b digital ; ‡c 4 3⁄4 in.
When your item consists of print plus a nonprint component, normally collate the nonprint as accompanying material in the 300 field:
+ ‡e 1 sound disc (4 3⁄4 in.)
+ ‡e 1 CD-ROM (4 3⁄4 in.)
+ ‡e 1 computer disc (3 1⁄2 in.)
‡a xxiii, 403 p. : ‡b ill. ; ‡c 24 cm. + ‡e 1 CD-ROM (4 3⁄4 in.)
If a disc contains both music (.wav files, for example) and text files (.pdf files, for example), describe it as a CD-ROM in the bib and MFHD.
As a general rule, delete angle brackets and the data they contain:
‡a v. <1-12,18>