This veteran Oklahoma quintet comes with a major league résumé(they've backed Dylan, Raitt, Clapton) and a knack for laying down barrelhouse boogie and hard country with uninhibited joy on The Tractors. Thanks to vocalist Steve Ripley's leering growl, their blue-collar outlook (''I might not be broke/But I'm badly bent'') is delivered with a chuckle. The Tractors are outstanding in their field. A

