Many contemporary composers, particularly those who compose in the genre known as spectralism, are incorporating harmonics trills into their music. The trills can create some beautiful sonic effects, and are especially effective when combined with tremolo, pressure techniques and ponticello.
There are many different possibilities for trills. The notes in the parentheses are those to be trilled to:
a) An Open String to an Open Node:
b) An Open Node to another Open Node:
c) A Stopped Node to an Open Node (sometimes called a “timbre trill”):
d) A Stopped Pitch to a Stopped Node:
e) A “Pressure Trill,” alternating between a stopped pitch on a harmonic node.
f) Double-Trills – Open Strings to Open Nodes:
g) Another Double-Trill:
h) A few examples of Timbre Trills
i. Open Node to Stopped Node (as seen above)
ii. Two open nodes yielding the same pitch
iii. Not technically a “trill”, but a similar timbral device.
iv. These also yield the same pitch.
Tips for executing trills:
- Start slowly! It’s often difficult to get the notes to speak quickly enough.
- Give slight articulations with the left-hand fingers, tapping lightly on the string for nodes and gently plucking the open strings.
- Try different bow speeds and contact points to find the best sound. Every unique cello, bow and type of string will have subtle differences.
Each of the following exercises works with one of the examples shown above. Repeat each bar until you can do it cleanly at that speed. Start at ♩=40.
Exercise 1. Use any finger you like for the harmonic note. Make sure to have good left hand articulation!
Exercise 2. Node to node. Lightly tap the string on each note.
Exercise 3. Instead of a normal finger-trilling motion, here you must hold your fingers in position for the first note and then use the arm to depress and release the string.
Exercise 4. This one’s a little easier than the last – keep the 1st finger down the whole time.
Exercise 5. Difficult! The finger articulation is important here.
Exercise 6. A slight forearm rotation takes care of this motion. The result is a subtle fluctuation in timbre.
Exercise 7. Both notes should be in place the entire time. Don’t swing the bow drastically from one string to the other, rather rock it gently starting from a double-stop position.
Exercise 8. Similar to Exercise 7, although now the thumb has two roles — to stop the D-string for the touch-5th harmonic and to play the harmonic “E” on the A-string.
Read on: Harmonics Glissandi