V.2

Video yourself tuning two strings so they sound like a single string and are stable. Make sure we can see your tuning hammer.

1. Pick a note between A3 and A5.
2. Mute one string. The other two strings now make up the double string unison, DSU.
3. Detune one of the strings of the DSU so that the DSU is obviously out of tune.
4. Retune that string to the other so the DSU sounds like a single string. It does not matter what pitch the final DSU is at.
5. When the DSU sounds like one string, play the note mf for 3 seconds.
6. Bang the key very loudly three times. (Stability test)
7. Play the note again, mf, 3 seconds long.