Which of the following is not an ornament?

• Trill
• Staccato
• Mordent
• Turn

Staccato is not an ornament.

The ornament that is not listed among these options is "Staccato."

To determine which of the given options is not an ornament, let's first define what an ornament is. In music, an ornament is a musical embellishment or decoration that is added to a melody or a musical passage to enhance its expressiveness or ornamentation.

Now, let's go through each option and understand if it is an ornament:

1. Trill: A trill is a rapid alternation between two adjacent notes. It is a commonly used ornament in music, and it adds a quick, vibrating effect.

2. Staccato: Staccato is not an ornament. Rather, it is a manner of playing notes where each note is deliberately shortened, creating a short and detached sound.

3. Mordent: A mordent is an ornament that involves a rapid alternation between a primary note and a neighboring note, usually played quickly before the main note.

4. Turn: A turn is a musical ornament that adds a small melodic flourish. It consists of the main note, the note above, the main note again, and then the note below before returning to the main note.

Therefore, the correct answer is: Staccato. Staccato is a musical technique, not an ornament. It is used to play notes in a detached and short manner, but it does not fall under the category of ornaments.