About Ligatures and Caps
Ligatures and caps are essential components to single-reed woodwind instruments like the clarinet and saxophone. Ligatures specifically hold the reed and mouthpiece firmly together while still allowing the mouthpiece itself to vibrate. Early on ligatures consisted of twine which was then tied around the reed. Modern ligatures are meticulously crafted from metal and contain gold nickel or silver plating - although ligatures made from plastic wire and leather can also be found on today's music market. Depending on the model and brand some ligatures can even be adjusted to improve the instrument's tone. Today's caps for woodwind instruments are also crafted with careful attention to detail and from flexible materials so they don't chip and continue protecting the reed/ligature/mouthpiece assembly.
It's important to understand how a ligature should be placed on a clarinet or saxophone. For optimal tone - and to ensure the reed isn't distorted and that vibrations can freely occur - a ligature cannot be overtightened. As for where it should be placed most professional clarinetists and saxophonists agree that midway between the file mark and the end of the reed is ideal (or halfway down the stock of the reed). The quality of a ligature will also have an impact on the instrument's feel and tone. Therefore the most recommended ligature and cap brands tend to be those that are known for a high standard of materials and craftsmanship.