I'm prompted by The Lovin' Spoonful, who were double billed with America here recently. Sebastian hasn't been with the band since '69, and Zally died a decade ago, yet they still get $50 a ticket. Last year, when the 4 Tops hit the casino circuit, the local radio spot used a classic Tops song with Levi on the lead. Is this right? Is it a ripoff? Why can one group get away with it and not another?