The greatness of Mac Rebennack, alias, Dr. John, also known as John Crieux, rests on his command of the musical use of idiomatic expression. Not a technically well-endowed singer, nor a great songwriter, he leaves his mark through the discipline and control he exerts over all that he touches.

It is by now beyond question that Elton John is a competent and classy entertainer. Few people who have achieved his popularity have succeeded in maintaining his standards for performance and professionalism.

The Beatles never sounded intimidated by their idols. They never interpreted old rock; they simply played it as well and as joyfully as they knew how. On 'Rock 'n' Roll,' John Lennon does nothing but interpret old rock.

To her audience, Janis Joplin has remained a symbol, artifact and reminder of late Sixties youth culture. Her popularity never derived from her musical ability, but from her capacity to link her fantasies of freedom and immortality with ours.

There is something complete about Stevie Wonder, and one senses that he is not only exceptionally important today, but will continue to be for as long as he chooses.

What makes the Stones' arrogance so divine is that we all believe that long ago and far away they weren't rich and famous but poor and struggling, just like us.

'Let's Get It On' is a classic Motown single, endlessly repeatable and always enjoyable.