Nothing about the music of Tom Harrell, the trumpeter and composer who is appearing this week at the Village Vanguard, is exactly what it seems. When he composed music for a large ensemble of horns and rhythm for his 1999 “Time’s Mirror,” it was hardly typical big-band swing; when he scored for strings in the 2001 “Paradise,” it wasn’t precisely chamber music; and when, for his most recent release, 2003’s “Wise Children,” he built an album around four well-known singers for whom he wrote songs with lyrics, it certainly didn’t sound like any pop vocal album I’ve ever heard.