Complex sentence: The technique of using a hard object against a plucked string goes back to a one-stringed African instrument called a "Diddley bow", which is believed to be one of the ancestors of the bottleneck style.
Split into simpler sentences: The technique of using a hard object against a plucked string goes back to the "diddley bow" derived from a one-stringed African instrument. The "diddley bow" is believed to be one of the ancestors of the bottleneck style.