The trick here is that the Cool Thursdays evening concerts at the Arboretum aren't supposed to be free. It's 10 bucks a head plus seven more for parking for these pop concerts, April through July, none in August, then a fall series throughout September and October. But you can hear them all without paying a nickel and also enjoy a very eclectic scene simply by paddling or sailing your small craft to the foot of the Arboretum, just off E. Lawther Drive near the Garland Road entrance to White Rock Lake. Call the Arboretum at 214-515-6518 for concert information or look on their Web page at dallasarboretum.org/concerts.html. If you do speak to them, ask about all their prices and then be sure to say the Dallas Observer told you it would be free if you came in your kayak.