The musical term con sordino refers to the use of a mute. There are many kinds available, all of which alter the timbre and volume of the instrument. Trombone mutes can be made of aluminium, brass, copper, plaster, cardboard, and sometimes plastic, all of which produce different tones.
Practice mutes are an invaluable tool for any trombonist. Sometimes called hotel mutes, they enable the player to warm up or practise in relative silence - something that can be of enormous benefit to anyone not wishing to disturb neighbours or family members! Practise mutes also make great teaching aids, as enormous improvements in tone are possible due to the increased air resistance.
In recent years, silent electronic practice mutes have become popular, as they allow the player to hear his instrument through headphones while not annoying those around them.
Read our separate online guide to mutes if you would like to learn more about this subject.