Who: Grand HallwayWhere: Northwest Court StageWhen: Monday, 3:15 p.m.Grand Hallway, a big symphonic pop band fronted by Tomo Nakayama, is one of Seattle’s unassuming little treasures that’s already well-loved amongst fans of big bands with accordions, keyboard, at least six different stringed instruments and sentimental lyrics about girls with golden hair and walking in the rain. Adding Shenandoah Davis to the band was a wise decision — her bright little birdy warble compliments Tomo Nakayama’s voice well — and today’s set made it really apparent how much progress the band’s made since its last release in general. Grand Hallway’s early recordings are all right. They’re nothing to sneeze at, but with the exception of a couple of songs, they’re not striking, either. That’s changed. The new songs the band shared today (they’re from the upcoming Grand Hallway album, the release of which the band’ll celebrate September 17 at the Fremont Abbey Arts Center) sounded so good as to convince me Grand Hallway may well become to Seattle what Loch Lomond is to Portland. I hope that happens, because these guys deserve it.