Hard disk for Music Server

I am building a PC as a Music Server.  Looking for help to pick hard disks.
Planning get 10 GB.

I am trying to get the best drives.....
Should I have say three 4 TB drives rather than one 10 TB?
How much capacity can one fill before it impacts performance? 70 %
Disk speed 5400 or 7200 rpm?
Brand of disk - HGST Ultrastar, WD Red, or WD Gold?

Thank you.
If you get 3 hard drives of 4G capacity, are you going to create a RAID 0 array to get your 10+G of space?
I worked for a hard drive manufacturer for many years and for music, it really doesn’t matter what type of drive you get. For music, you won’t see any difference in speed between 5300 or 7200 rpm. Actually, I even recommend against ssd for music. If you are using Roon or another app that has an index to your music, keep the index in memory or place that on ssd, that will give you better performance. If you build a RAID array or buy a single large disk, make sure you get a bigger disk to use as a backup
If you go with the  WD Red watch the model number. There was some recent controversy about the labeling and the storage method. See  https://arstechnica.com/gadgets/2020/06/western-digital-adds-red-plus-branding-for-non-smr-hard-drives/ 

Using 4 of the Red WD40EFRX 4TB in a RAID 5 configuration in my NAS with no issues. 
Raid 0 offers no backup, it only spans more than one drive into volume (s) Very bad if there is a drive failure. Raid 5 is good but difficult to repair if there is a failure. 1+0 is much better, gives you failure, hot swaps without downtime or data loss, but during the failure time you will suffer data SLOW downs big time, on a network sharing the files..

More smaller, faster, drives with STRIPPING, will blow your mind with speed. SSD RAID 1+0, 4-10, 2 gig SSD drives, Hot rod buddy...
FTH comes to mind, Faster than hell.

I ran SCSI II raid on my old Novel networks, for some manufacturing software...The 60 meg BOOT drive weighing close to 60 lbs each. Priam, drives with 10" platters? I think......OLD SCHOOL...LOL They were Raid 5 X 5s The rack was close to 400 lbs, the system 36, IBM ran on 220-240.  What a watt sucking setup....Sure was cool, though...HOT, was more like it, come to think of it.. Made barrels of all things...Paper, metal, HS, polys, overpacks....

Just curious about your need for 10 TB of storage - that's a lot!

Do you currently have a large collection already on hard drive that you are simply going to transfer? Or, do you have a CD collection that you are going to rip? If that latter, it it is going to take you a long time to rip 10 TB of CDs.

And, instead of ripping everything, you might think about combining a streaming service service and then ripping only those CDs that are not available from streaming. File the rest of your CDs away and just add them as needed and/or you find the time.

Of course, if you have something else going on that needs the 10 TB of storage (videos, photos, business, etc.) then ignore the above.
As someone who has a goodly amount of experience building my own very fast computers (which among other things I use for editing of 4K video material, which is a very challenging task for a computer), here are my thoughts:

I agree with @rbstehno that you don’t need speed. Also, given especially the need for a backup drive or drives I would choose a small number of large drives, rather than a multitude of smaller ones. And I don’t see any need for complicating things with RAID. Keep it simple!

What I would do is use a single 5400 rpm 10 TB drive for music storage, another 5400 rpm 10 TB (or larger) drive for backups, a self-powered external usb-connected 10 TB drive for a second backup, and something like a 7200 rpm 1 TB WD Gold drive as the system drive (i.e., the drive containing Windows and programs). (That’s more capacity than you’ll need for that drive, but I don’t think the Gold drives are available in smaller capacities). Or if you envision using the computer for unrelated purposes where a faster system drive may be desirable, consider a smaller SSD, perhaps even a Samsung M.2 2280 NVMe drive if your motherboard can support it, those being **extremely** fast.

To back up the music files I would periodically simply copy the files from the music storage drive to the other backup drives, telling Windows to skip files that are already there.

I would also consider using a disk imaging program to periodically create images of the system drive, storing the images on one or both of the backup drives. In the unlikely event of failure of the system drive that would avoid the necessity of having to reinstall and setup Windows and your programs. I suggest that you consider Terabyte Unlimited’s "Image for Windows" program, which I have used for many years with great results, or Acronis True Image, which seems to be fairly popular.

Finally, FWIW, my perception is that HGST drives (HGST now being a brand of WD) are not very popular these days, as evidenced in part by the limited number of reviews their recent drives seem to receive at NewEgg.com.

Good luck. Regards,
-- Al

I think more info is needed. Is music the only thing you're putting on the drives?, how many people will access at any one time? Have you considered backup? Is this going to be a headless server running linux? 
I spent over 42 years in IT with over 30 years in the performance end of things including storage systems costing over million dollars (EMC storage), the last 10 years actually working for a solid state/hard disk manufacturer. You always need a backup no matter what raid array you use or even if you spent over a million $$ on a disk subsystem.
If I was going to build an array for music and even for video, I would go with a raid 5 or 6 which gives you better reads at the expense of slow writes. But I also don’t like using software raid, if I was going to build a raid system I would buy a 4 or more disk system that provides the difference raid configurations.
All of my systems at home, either Linux or OSX, use an ssd for the system disk but use your typical 5400 rpm drives for the other uses.
Just FYI, you do not need speed, but if you plan to store 10TB, you probably want reliability.  I suggest an external, network enabled NAS.

Doing RAID with a PC is a dangerous affair.  If the motherboard dies, you may not be able to recover the RAID set. 

I'd go with cheap drives in a decent NAS enclosure connected via Ethernet.
I’d go with cheap drives in a decent NAS enclosure connected via Ethernet.
That’s certainly a reasonable suggestion, Erik, **if** (IMO) it is supplemented by an additional backup on a completely separate drive or set of drives. For example, if the power supply in the NAS enclosure goes berserk it could simultaneously wipe out all of the drives that are contained. Or if the controller circuitry in the enclosure fails at some point in the future, and the same or a similar enclosure is no longer available, depending on what RAID mode is being used the data may be unrecoverable.  Or if there is a latent bug in the controller firmware, that would only surface rarely, who knows what can happen.

Over the years I’ve seen user comments at NewEgg describing exactly those sorts of experiences with various such enclosures, resulting in loss of all of the data.

@rbstehno had it right:

You always need a backup no matter what raid array you use or even if you spent over a million $$ on a disk subsystem.

Best regards,
-- Al

Again raid 1+0, look at how it works. Very fast, redundant, and hot swappable...Stripped, and mirrored. Yes I’ve built a hot rod or two..

In other words you could pull a drive, replace it. Take the drive you pulled and start a migration, to build another complete system. Space shuttle crap, and a fast way to RE-build a downed system......I would never need it...

The biggest difference between RAID 5 and RAID 10 is how it rebuilds the disks. RAID 10 only reads the surviving mirror and stores the copy to the new drive you replaced. ... However, if a drive fails with RAID 5, it needs to read everything on all the remaining drives to rebuild the new, replaced disk.

I’m not to fond of Software RAID either, I like SCSI, and onboard, disk low level management... The OS or NOS, well you can get as teckie as you like...LOL I like easy... Not lines of code to just create a BOOT strap, to see a disk, to read a disk, then boot from a 60 POUND, 60 meg hard drive. An IBM 36 was that way, that I maintained for quite a few years...

When were talking Backup, that should be a given, guys.. Really, who doesn’t have a tape backup, or at least a CD backup. A HD or SSD will ALWAYS fail, it’s just a question of when...

Another thing, a PS failure, very seldom leads to a drive failure. I’ve never seen one, lower quality PS of old could lead to drive failures, very rare though. Like MFM, RLL, and ESDI drives, before SCSI, and WAY before, any IDE stuff. Again it is a single failure, BUT no data loss. One of a few reasons for RAID to begin with.
Speed, Reliable, not expensive, redundant, and not necessarily a proprietary part needs to replace a failed one...
Replace a Seagate with a Maxtor, give it a physical ID, terminate, and away you go.....

One other thing, even though software raid is not the best... It’s still pretty good. The problem, the software usually complements the drive spec only, not the interface between a SCSI driver board (with its own onboard buffer, ROM, and HI speed RAM). So if you lose a drive, you need to replace with the same or use a software patch.. Even more proprietary..
Good place to get malicious, if you’re handy with a GOOD keyboard break routine, and a few other tricks, to speed the console up...Wipe someone elses drive pretty quick. Command line access is pretty hard on a good SCSI board..You ain’t gonna do it over a phone/LAN/WAN/WiFi, or any way. It would be real tough...You gotta be there to access the bios.

Now think, three board per server each board can run 14 devices and one ID for the boards, you have 5 servers. Each drive is 10T, spinning at 10,000 rpm....I wonder how many miles that is in a year? 2.5" or 3.5" 2-6 platters, Sorry I ran out of fingers and toes... It's a lot....Carry the 1, geez that one hell of a cipher!!! Ok brainiacs, step up, way out of my league.. I'm simple.

I’ll ponder that while I feed the chickens...

If you are worried about data recovery or losing a disk on a raid 5 system, then use raid 6 which has 2 parity drives so you can actually lose 2 drives and still keep working. For casual use around the home for sharing music and video files, an external raid 5 (Or 6 if you can find it) will be the cheapest and still provide the read speed that you need. Ripping will be slower but who cares, you put a dvd in and come back in 15 mins to eject the dvd.
watch out for home cloud drives, they are slow, painfully slow.
You can create your own NAS drive by hooking up a drive on the back of your router that you can share. Pretty easy and no cost. I use a dedicated server with most of my hard drives and SSD’s attaches to it to do all file sharing and backups from that server In the early mornings. It’s main task during the day and night is running Roon, and soon Plex.