We're not saying that "crossover" is a bad word. We're just saying that it doesn't apply to the Bronx-based bachata group Aventura, mostly because you can't cross over to "here" when you were never really "there" in the first place. Like the group's lead singer-songwriter, Anthony Santos, most of Aventura's core audience is first-generation American with strong roots in the Dominican Republic or other Latin American countries. Bilingual and bicultural, the members of Aventura grew up listening to both American and Latin music. When it came time for the group to do their own sound, it was natural to go for a mix of the two rather than the hardcore purist approach. This Houston stop is just one of a 21-date tour across the country in support of their latest CD, The Last. The release, which includes appearances by Ludacris, Wyclef Jean and Arturo Sandoval, blends R&B, reggaeton, rock, trio and traditional bachata styles. Released in June, Last debuted at No. 1 on Billboard's Top Latin Album charts, where it stayed for more than 15 weeks, spawning three top singles and reaching double-platinum status.