Thanks for your help.
I was looking at the...
Corsair Voyager 1tb
Seagate wireless 1tb
I do have a laptop but it is on it's last legs so I was trying to avoid having it running whenever I listen to music.
I'm open to suggestions on better set ups too.
Keep in mind that those type of drives are intended to be used such that you "drop" your connection to your normal WiFi network and connect directly to a WiFi network that the drive creates. Traditionally, this mean that when you did this, you were ONLY connected to the drive, but not the Internet and your local network.
Now, from reading some of the reviews of the two drives you linked to, it appears that both offer an "pass-through" feature that allows you to connect the drive to your regular WiFi network in some way that allows any devices connected to the drive's WiFi network to then connect to the Internet (and presumably any device on your local network). Assuming this does mean that you can connect to local devices on your network (which in theory should be a good assumption), then it should be possible to do what you want to do in theory when using the "pass-through" feature.
In order for it to work, the app that you use to stream the music from the drive would need to support Airplay. Traditionally, the app that you use is an app from the drive's manufacturer. This seems to still be the case for the Corsair drive, but at least one of the reviews on the Amazon site seemed to suggest that any DLNA app could be used to stream music from the Seagate drive. Looking at the Corsair app in the App Store, it seems to suggest that it supports Airplay, so in theory using the "pass-through" option, you could stream music from the drive using the Corsair app and then stream that music to speakers connected to an Airport Express. For the Seagate, it appears their app also supports Airplay. If you want to sue a generic DLNA app with the Seagate, assuming it can in fact allow access to generic DLNA apps, then you would need to check the DLNA app on whether it supports DLNA.
Now, I have not used any drive that offers a "pass-through" feature, so I cannot say for sure if it will work as you want. It seems that it should based upon the way the "pass-through" feature is described, but I cannot be 100% sure.
I should also note that assuming the "pass-through" option works, any music that you play would be required to NOT be copy-protected. This should be true to any music that you bought through the iTunes Music store as Apple ditched copy-protection a number of years ago…but may not be true for any music that you purchased a long time ago from Apple, unless you re-downloaded it from the iTunes Store. Any music that you rip from CDs will definitely not be copy-protected.
Lastly, it does appear that the Corsair can be connected to your network by way of an Ethernet cable and used as a traditional NAS drive. In this mode, presumably, you can stream music from it using a DLNA app, but it is not clear if that is true. If so, then if that DLNA app supports Airplay, then you could use that mode as well.