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Extremely simple sounds like a clap, snap, two random objects hitting each other, etc. have no part in Harmonics. The sound must engage some level of emotion in the user. The only example of a simple sound causing a Harmonic Effect is if the user hearing it can attribute something to it. Say, a Force User was attacked by dogs in his/her youth and was traumatized by it. The sound of a dog's bark could give this person enough fear or hatred, if they have control over their fear they can then use a Harmonic technique that fits with in their state of mind. (Obviously this person is using the Dark Side then. Most Light side users may find Harmonic difficult to harness.)

On the other side though, when a piece of music or a song takes in Force User fully the acts they can work can be astounding. This leads me to the first two techniques.

Praise to the Artist

Here is when someone is total captivated by a musicians performance. Those who become entranced are now subject to the will of the Force using musician. As long as the song continues and the person can hear it, that person (or persons if the User is naturally strong enough) are subject to the will of the User. Similar to the Mind Trick and like most hypnotic acts the subject can not be coerced in to suicide.

In Concert

This allows multiple Force Users to actually put their strengths together. A "The whole is greater then the sum of its parts" sort of thing. This is normally used in tandem with other Harmonic techniques. This is perhaps the only technique where singing can be as powerful as an instrument.
Note: Most vocal cords of most species do not have the range of an instrument, thus limiting its usefulness in Harmonics. Those who have the talent and training in singing can work equal wonders of musicians though (think Opera singers).

Also, a simple whistle (of the mouth or the instrument) can cause disturbances near by that will disorient those around, but most Force Users can over come this fairly quicly. Those well experienced and powerful in the Force will not be affected at all. If you can hold a trill whistle and attack at the same time then you may be able to take out an enemy or two though as long as they remain disoriented.

Force Slip

The Force User(s) must be experienced in the Force and have at least a combined power of above average. The User(s) must first strike the lowest note they can achieve. Meditating on that and listening to the Force shall allow them to be inspired as to what melody to play next. Once in harmony, a Slip Bore will open. This is quite literally an entrance to the "blood stream" of the Force. (Think as if space is its skin, then this is the innards.)
While in transport, the User(s) must keep listening to the Force and make transitions as necessary. To exit where you want to, you must think about where you want to be and think as if you were touching the Force there. The melody necessary for going there will start to be heard and the User(s) must make the transition smoothly.

If the melody ever stops while in transport the ship will be forced out at what seems to be a random location. If the stop is do to over exertion then those involved in the playing/connection could be stuck in the Slip while the ship falls out.

Bonesinging is a Randir style of Force Harmonics and is the primary method the Randir use to manipulate wraithbone. Bonesingers are the builders of the Randir race and to augment their ability and better produce musical notes, they can use instruments.

A bonesinging instrument: