Roy, Could it be you're hearing the first two thirds of a Ruby-crowned Kinglet. I have heard them do just part of the song. Another long shot is the alternate song of the Golden-winged Warbler. Nothing like the "bee-bzz-bzz-bzz" we're use to. I've heard in NJ, but never in Vermont, and it's not described in any field guides I know, but it might fit your bird. Sorry I can't describe it in detail. It's been a long time. We spent a half hour on a World Series trip trying to identify it before we saw it sing. Bruce Peterson On 4/29/10 11:48 AM, "Roy Pilcher" <[log in to unmask]> wrote: I first heard the song at Aitken State Forest on 2010-04-22 and then again today on 2010-04-29 also at Aitken State Forest but approximately half a mile separation. From the "heft" of the song, it would suggest a warbler size bird. The song was intermittent. The song seemed "hurried" almost "explosive". Bird was up slope when heard on 2010-04-22 in what appeared to be pure deciduous woods. Today, 2010-04-29, the song came from a small stand of tall spruce/fir, [my tree ID is lacking] and high up. Song is a trill fallowed by a chu chu chu. Most times there are three chu chu chu's but occasionally two or four. Caution! I may not be hearing the full song as I have lost and am losing the higher frequency sounds. If I get some leads I can check with the Cornell site, but hopefully there will be the opportunity for a some additional ears! Thanks in anticipation. Cheers, Roy Pilcher The Gables at East Mountain, Rutland, Vermont Speaking the same language.