UNLIKE most other travelling rock circuses, it pays to do your homework ahead of catching a Bob Dylan show. Although he has been touring constantly for more years than most of us have been counting, no two shows are anything close to the same, either in terms of content or quality. Fortunately, numerous websites exist to satisfy any such cravings for pre-show pointers and Dylan trivia.

Of course, he has dug his music into some deep troughs over the past 20 years, but advance reassurance comes from the fact that he has retained the services of the band that provided such a nimble and appropriate backdrop on his last visit to Scotland less than 12 months ago. The combination of jam session fluidity and well-practised tightness remains, as does the structure of the set, but the songs and mood are considerably different from his SECC show.

The similarities end with the length of the set and his well-worked live formula that involves reinterpreting his greatest hits next to rarely unearthed treasures from his back catalogue. To this end, the melodies of Mr Tambourine Man and Like a Rolling Stone may be familiar, but it would take some skill to sing along to the choruses such as Dylan's vocal improvisation. In fact, it is the less expected songs such as Tell Me That it Isn't True and Stuck Inside of Mobile with the Memphis Blues Again, that seemed to set the agenda for the show.

Last year offered Dylan's most enjoyable extremes - sparse and acoustic on the one hand, with visceral rock'n'roll on the other. this year treads an even path between the two, a generally subdued mixture of lilting country and gentle blues where pedal steel and harmonica respectively take centre stage.

It may be the setting - Scotland's most panoramic car park - the rain clouds, or the abundance of Barbour jackets in the crowd that contribute to such a mellow performance, where even the encore with the likes of Knocking on Heaven's Door, Highway 61 Revisited, and Blowing in the Wind, failed truly to ignite.

Now in his seventh decade, Dylan may frequently deviate from greatness, but he remains a fascinating, laudable, and often enjoyable live act.