Music: In its biggest coup since being purchased in 1992 by a group of investors, the small royalty-collection organization SESAC has signed agreements covering the repertoires of songwriters Bob Dylan and Neil Diamond. The nonprofit American Society of Composers, Authors and Publishers (ASCAP) formerly collected and paid royalties for Dylan and Diamond. Terms of the multimillion-dollar deals were not released. More than 300 Dylan songs, including “Blowing in the Wind” and “Mr. Tambourine Man,” are covered, as are more than 200 Diamond songs, such as “Solitary Man” and “Sweet Caroline.” SESAC is owned by music industry veterans Freddie Gershon, Ira Smith and Stephen Swid, with backing from entertainment investment banking firm Allen & Co.