Which of the following is not an instrument mentioned with a specific range?

The correct answer regarding the instrument not specified with a specific range is the trumpet. When discussing musical instruments and their ranges, glockenspiels, modern pianos, and harpsichords typically have defined ranges. For example, the glockenspiel has a specific pitch range usually spanning about two and a half octaves, while the modern piano has a well-defined range of 88 keys, covering seven octaves plus a minor third. The harpsichord, known for its unique sound, has a range that can vary depending on the specific instrument but generally is also defined.

In contrast, the trumpet's range can be quite variable depending on the player's skill, the type of trumpet (such as B♭, C, D, or E trumpets), and the specific repertoire being played. This variability often leads to less focus on a specific range in educational contexts, making it less likely to be mentioned alongside the other instruments listed, which have more standardized ranges. Therefore, while the trumpet does have a range, it's not specified in the same way as the other instruments in this context.