Using the Piano Display button at the bottom left of Pro-Q's interface, just above the
bottom bar, you can toggle between the normal frequency scale and a piano keyboard display, via
which band frequencies can be adjusted as well. The highlighted keys correspond to an 88-keys
grand piano layout, ranging from A0 (27.5 Hz) to C8 (4186.01 Hz).
For every band in the display, there is a corresponding dot on the keyboard. You can interact
with the dots in two ways:
Click the dot once to quantize the associated band's frequency to the exact musical
note.
Click and drag the dot to change the frequency while keeping it quantized to musical
notes.
While the piano display is active, parameter value displays that show a band's frequency will
also show that frequency as a musical note (including cents offset). Note that at any time, also
if the piano display is not showing, you can enter frequencies as musical notes. For example, you
can double-click on the Frequency knob in the band selection controls and type "D#5 +13", or
"A4".
Tips
To quantize a frequency without using the piano display, just double-click
a curve dot in the display or the Frequency knob in the EQ controls, and enter a value like
"A4" or "C#2".
Pro-Q 2 displays the C4 key as middle C, following the most used Roland standard. Note that some DAWs (e.g. Cubase) might use a different format, showing C3 as middle C (the Yamaha standard).
By default, the piano display key that matches the frequency at the current mouse position
is highlighted, and a small label shows its note number. You can turn this feature on or off by
clicking Show Frequency On Hover in the Help menu.