Article: These can become a bit tricky. To play notes above D', a technique known as "pinching the thumb hole" must be used. Cover 2/3 to 3/4 of the thumb hole using the tip of your thumb. Tighten your lips slightly and blow a little harder than usual. A semitone is a sound that's halfway between one note and the next, like the sound made by the black keys on a piano. You have already learned one of the most popular semitones - that is, F#. Two more semitones that you should learn are Bb and C#'.   The fingering chart for Bb is: 0 1 - 3  4 - - - The fingering chart for C#' is: - 12 -  - - - - You can practice these semitone notes by playing a little ditty called Baa Baa Black Sheep: D D A A B C#' D' B A, G G F# F# E E D Once you have mastered the notes, you can work on your vibrato technique. A vibrato allows long notes to resonate, creating a nice dynamic effect. There are several ways to accomplish this:  Use a diaphragmatic vibrato. Control the flow of air into the recorder by tightening and contracting your diaphragm. Say, "heh heh heh" but do not cut off the flow of air entirely. Use a tongued tremolo. Say, "yer yer yer yer yer yer" using your tongue to control the airflow. Use a finger vibrato. While not being a very practical choice for a sustained vibrato, this method is commonly referred  to as a trill. Alternately finger the note and the next higher note. Do not tongue each note, but rapidly play an A B A B A B A sequence. These are created by sliding the fingers off the recorder in quick succession to create a sliding sound.
What is a summary of what this article is about?
Practice playing high notes. Learn the semitones. Work on vibrato. Use glissandos.