I hung a Woodstock Little Gregorian Chime from my suet feeder. The chimes ring when the birds land and feed, and ring even more when the birds take off. I know when birds are feeding on the suet even when I can't see the feeder, because I can hear the ringing of the chimes.
I can even get a pretty good idea of what birds are there by the sound of the ringing. The small birds like the chickadees and nuthatches make a soft ringing, the large birds like the jays and flickers ring loudly, and birds like the downy woodpecker create a soft rhythmic chiming with their hard rhythmic pecks. And when the larger birds take off, it often sends the chime spinning, the tubes flaring out in a circle from the centrifugal force. (And by the way, sometimes people have asked me, "Doesn't it bother the birds?" Definitely not, birds love music, that is why they make music themselves! They especially like music in high registers.)
Here is a photo with a flicker feeding. This photo has two flickers on the feeder, a father and his fledgling. Notice how the bird causes the chimes to swing.
G.H., Portland, OR