In order to get impressive results with the Go APE system, you need to use all three elements of the Go A.P.E. System: DSU, NSL Analysis, and Beat Speed Windows.

However, this lesson shows how anyone can instantly tune faster by using this simple DSU technique called Beat Matching. DSU stands or double string unison which is a technique where you tune two strings of a unison to sound like one and then judge the pitch using beat speeds.

The procedure for quickly tuning pure intervals (like a pure 6:3 octave for example) is as follows:

1. Tune the DSU clean.
2. Play the interval.
3. Listen to the speed of the beating coincidental partial in question. (If it’s not beating, that means the interval is pure. You are done! 🙂
4. Detune string #1 of the DSU in the direction you want to go (use a check note to know which side of pure you are on) so that the DSU is beating at the same speed as the out of tune interval in step 3. Listen at the same coincidental partial in step 3.
5. Retune the DSU clean by tuning string #2 of the DSU.
6. Check the interval for purity, by listen directly or by using its check note.

This technique is for octaves that are out of tune. You need to be able to hear the beating of a specific partial in order to use Beat Matching. If you can not selectively hear any specific beating partial pair in an octave – 2:1, 4:2, 6:3, 8:4, etc. – then you can’t use this system. You will need to train your ear more.

While this technique can speed up your tuning, the real power of DSU is that you will not be able to hear the beats unless your unisons are clean.

Many techs think their unisons are good enough but they are not good enough for DSU, and for some discerning customers.

Learn DSU and your unisons will be clean enough for any concert pianist.

Watch this video for a demonstration of how I tune bichords using Beat Matching. The beats are filtered so you can easily hear them.

In this video, I tune 5 bichord octaves as pure 6:3, both strings, in 44 seconds! That’s less than 5 seconds per string! It’s not me, it’s the method. Anyone can do this with training.