Joni Mitchell carries such a weight of other people's memories on her narrow shoulders that the demands made on her at public performances are doomed to break even the best will in the world. For many years it has been Ms Mitchell's will not to play UK concerts so now to cram London into one evening at the certifiable Wembley Arena, and, to boot, to use the occasion to promote a new album, it inevitably transpired that the applause, although generous, was tinged with disappointment.

   It is quite understandable for artists to want to produce new songs even if, on first hearing, they may seldom demand a second, but I find it harder to forgive her playing Wembley.

   And yet for moments, when she sang Case Of You, alone with a lap guitar, all the old magic survived. The clever lyrics, the poetic melody, the intimate confessions of the songs which comforted millions of romantics a decade ago hushed the packed concrete blankness of the arena in an intimacy outside the scope of any rival performer.

   There was not much of the Blue period, or of the earlier Woodstock whimsy, although Big Yellow Taxi survived well. For the second half it was Joni Mitchell plus band, and many of the new songs, which show her up-tempo, up-spirited, and rather conventional. It is interesting to watch her perform Presley's You're So Square, but wonder why she bothers. She seems to have escaped into her earliest musical memories and snatches of old pop classics, like Oh My Love, are slipped into the contemporary compositions.