1. Hold the trombone correctly. The bell of the trombone should be pointed slightly upward, and your right hand should be positioned between the first and second slide positions. Your left hand should be positioned near the third slide position.
2. Buzz your lips. Begin by buzzing your lips together without playing any notes. This will help you to feel the correct embouchure (lip formation) for concert A♭.
3. Play the note. While buzzing your lips, slowly move the slide of the trombone until you hear the note concert A♭. The slide should be in the first position.
4. Adjust your embouchure. If the note is not in tune, make adjustments to your embouchure until it is. You may need to change the amount of pressure you are using on your lips, or the angle at which you are holding the mouthpiece.
5. Practice playing the note. Once you are able to play concert A♭ consistently, practice playing it in different contexts. Try playing it as part of a scale, or in a song.
Once you can play concert A♭, practice playing higher and lower notes in the instrument’s range.