Jensen’s MainStage—the De la Vina Street venue put together by Jensen Guitar & Music Co. that’s been popular with amateur musicians and the under-21 crowd—closed this week due to dwindling cash. Around since 2008, the stage hosted RockCamp for youngsters and was used by everyone from promoters to heavy metal bands to fledgling singer-songwriters. Owner Chris Jensen said to keep the venue going just wasn’t fiscally feasible because his business has been hurt by the economy and it didn’t make any money selling food or alcohol, which is how most venues earn a large portion of their profits.