Tutankhamun's trumpets
Jeremy Montagu  examined the broze trumpet in the 1970s. It consists of two sections. The slightly conical body is from a rolled sheet of copper alloy between 0.2 and 0.25 mm thick. It has been soldered lengthways with a "very skilfully brazed meander joint ... smoothed to a perfect finish", yet is "slightly rough" internally, indicating that (as might be expected in a ceremonial instrument) appearance was of greater value than acoustic performance. The bell is of a different, thinner material: an electrum-like alloy of gold, between 0.1 and 0.13 mm thick. It is without a visible seam, probably "burnished until the gold simply flowed together". The 3.25 mm thick ring that forms the mouthpiece was probably also made of electrum. The ring is apparently not fixed to the body, Montagu suspected that although it was possible to generate three notes on the instrument, the highest note would not have been sounded; besides being an effort to produce, the trumpet's construction could not have tolerated it. The lowest note does not carry far, leading Montagu to hypothesize that only the middle note was used in a rhythmic signaling code.