Here's a bit we're adding to the Shopping for C Melodies article:
As a reference, the following picture shows the relative sizes and shapes of the Alto, C Melody and Tenor, respectively. You can see that the C melody (in the middle) is a little smaller than the Tenor and a little longer than the Alto.
This C Melody is what they call “Tenor” C melody, because it has a Tenor-style neck. However, you can see that the neck is almost as large as a “real” Tenor’s neck, which makes it seem disproportionately long compared to the body of the instrument.
Some C melodies (especially Conns) have a neck that looks more like an Alto’s neck. But it's easy to tell an "Alto" C Melody from a "real" Alto, because the bell is so much longer and skinnier than an Alto's bell.
Finally, you will notice that only one of the lowest pads is on the right side of the horn (from the player’s point of view). This is a characteristic of all Alto, C Melody, and Tenor saxophones built between 1914 and 1926 (and a few built up until about 1932, which was, incidentally, about the last year C Melodies were built in Europe or North America.
After that, most horns (except Selmer’s Paris-built models) had both of the lower pads on the left side of the bell until about 1967, when they started moving, together, to the right side of the bell. By about 1985, all the lines had moved both the low B and Bb pad to the right side of the bell, imitating Yamaha’s imitation of Selmer’s Paris-built horns. So if you see a saxophone with both pads on the same side of the bell, it’s certainly not a vintage C Melody. (A few cheap Chinese C-melodies have been built this way, but I wouldn't advise going that direction.)
