This is a playable Bb Herald Trumpet. You can listen to me playing it here: http://sdrv.ms/14Sdctv I printed it on a MakerBot as 10 pieces which were assembled and then bonded together using acetone. It plays about 20 cents flat, likely because my Bach 3C mouthpiece doesn't insert as far as my design intended. The tone quality isn't bad. I rendered it using ReplicatorG. I set the slice layer to 0.2mm, the shells to 3, and the infill to 20%. The STL files were generated using a C# program I wrote. The mathematical model for the bell is loosely based on a paper which appeared in a January 2011 issue of Journal of the Acoustical Society of America by Charles Macaluso and Jean-Pierre Dalmont called "Trumpet with near-perfect harmonicity: Design and acoustic results". The pieces print with fins that stabilize them against wobbling or tiping during printing. The fins are designed to snap-off after printing. It has been pointed out that the fins may not be necessary; a one-line change to the C# program can remove them; if you try it, let me know how that works. PLEASE improve this! Next steps: Thanks to my employer, Microsoft, for lending the MakerBot on which this was printed.