Singer-songwriter Joni Mitchell, who has performed only a handful of shows in the last 15 years, will join Bob Dylan on a West Coast tour that includes concerts May 21 and 22 at UCLA's Pauley Pavilion and May 23 at the Pond of Anaheim. Van Morrison had been announced as co-headliner for the tour, but a spokeswoman for the Irish singer said Tuesday that he had never officially agreed to play the dates.

Mitchell's last L.A. performance was on Jan. 26, 1995, when she played at the Gene Autry Western Heritage Museum. The Rock and Roll Hall of Famer has not toured since 1983. Tickets for the Dylan-Mitchell shows go on sale Monday at 10 a.m.

Mitchell is also among those scheduled for "Stormy Weather '98," an April 16 benefit concert for Walden Woods at the Wiltern Theatre; Natalie Cole, Toni Braxton and Shawn Colvin are new additions to that bill.