In this town, one supposes a Tuesday night in the middle of the week can stretch only enough to contain a Cinco de Mayo warm-up, regardless of what the calendar says. The real action, from Federal Boulevard cruisers to the big event in Civic Center Park, will probably heat up over the weekend. But it wouldn't hurt at all to get into a festive mood tonight at the Colorado Symphony Orchestra's free annual Un Toque de Mexico concert, would it?
Beginning at 7 p.m. in Boettcher Hall, Denver Perfor
