That’s just the way it is/Some things will never change. At least that’s what Bruce Hornsby said back in 1986 on “The Way It Is.” But even though Hornsby has swung in and out of the spotlight since then, this perennial sideman and former Grateful Dead keyboardist — a position that’s seen as much turnover as Spinal Tap’s roster of exploding drummers — has never been too far from the action. With the release of his aptly titled latest album, Halcyon Days, Hornsby is again center stage as he calls on his own roster of impressive sidemen (Sting, Eric Clapton, and Elton John among them) for assistance. The result is an album that is both delicately nostalgic and resolutely optimistic. Optimism is in short supply these days, so it’s a good thing Hornsby always has plenty to go around. That’s just the way it is/But don’t you believe them.