Repurpose iMac as Server?

Hello,

I'm running a MacBook Pro and have just invested in a Network Streamer for my hifi.

I have an old iMac, which I occasionally use for work - particularly now - for the screen size - but don't store any files on here - just connect to my work network.

I've heard an old Mac can be re-purposed but am unsure how to go about it. The main use would be to store my ripped CD files and act as a music server. Ideally, can the iMac be partitioned and partly used as a server and partly as an iMac?

It's a late 2013 3.2 GHz Quad-Core Intel Core i5
Memory: 8 GB 1600 MHz DDR3
Graphics: NVIDIA GeForce GT 755M 1 GB
1TB (7200-rpm) hard drive

Any advice would be greatly appreciated.

Thanks, Matt.