How to obtain clock signal from crystal oscillator?
It is not a quartz oscillator, it is a quartz crystal, which needs to be connected to an oscillator circuit to make a clock signal. Many crystal datasheets and application notes have a diagram how to build it with unbuffered CMOS inverters, such as 74HCU04 or CD4069. I would not build it from a 74LS04, but with some fine tuning it generated good enough clock for YM3812. However, it does not specifically need this rate, but it is a common clock for it in many systems (e.g. in PCs).