Looking for a monolithic VCO chip

Hi guys,
Just wondering if anyone can recommand any VCO chips that works in audio frequency range, ideally covers from 20hz and beyond 20khz...

I am looking to build an analog synthesizer but would like to keep the circuit compact, I guess I can also use some signal generator chips.

Thanks in advance!

The most commonly used chip is ICL8038 (or the new MAX038 up to 20MHz!) , XR2206

Wow....thank you so much Sebi!!!!

Really appreciated!!!!!