Interesting take on the challenge. While I know you didn't have a choice, a flat background of maybe a darker colour would have improved this shot - it would have really contrasted nicely with the instruments.
This is a hard shot to make, the lighting and reflections make it difficult to isolate your subjects but I think a different, more straight on angle might have emphasized the 'one is missing' idea. It also seems like a bit of a stretch for the challenge.
strange crop... or you should have filled the empty rack with another one. here i would think 'less is more', meaning if you had only the top 2 in your pic with good use of dof, you surely would have had a better response.
Good idea, Good capture would have liked it better without the price tags hanging there. May have gotten the idea of family across more if besides the cornet and trumpet thier was a picalo trumpet, maybe flugal horn.
I understand the concept you were going for, but I don't feel like this works very well. The display wall is unattractive, as are the sales tags. Too many distractions to lead the eye away from the horns.
Meets the challenge. Well lit, exposed and focused. I might have cropped it to either get all of or exclude topmost instrument. Nice reflections. Rotating the image diminished it in my opinion.