Ok so your playing the music over a share to another computers hard drive and having issues with transfer speed?
Here are all I can think of that affect speed of file transfers for your setup:
1.) Wireless Signal Strength ( Further away with weak signal sync's slower data rate than strong signal )
2.) Wireless Noise ( other wireless devices on same channel but different network competing for airwaves )
3.) Wireless B, G, N etc ( maximum data transfer speed is dependent on what wireless connection your connected to as for there is a maximum throughput speed. Such as if your connecting a new computer over wireless to a 10 year old Wireless B network, Your Wireless adapter is connected to B speed/bandwidth limitation.
4.) Wireless Adapter USB Addon or Card .... ( Wireless Cards internally installed are better than an external USB connected Wireless Adapter in some situations where the USB BUS is busy with External Drive connected to it etc to where the USB controller itself is flooded with the data juggle. )
5.) Computer that the wireless is running on also affects it, CPU ( ability to juggle the multitasking ), RAM ( ability to multitask without having to rely so greatly on virtual memory of the hard drive or SSD ), Hard Drive ( virtual memory and caching of data located elsewhere )
6.) If not peer to peer wireless and a wireless access point of router is used the quality and performance of the access point or router that the data is passing through as a relay point can also cause the speed to be slow.
7.) All other wireless devices that are using bandwidth will affect the transfer rate between 2 systems as for the access point of router that the systems are all going through is busy handing all packet requests and so performance dives with more devices requesting and sending packets through wireless access point or router.
8.) Lastly on routers mainly. Many of them also have wired connections available. Data transferring over the wired network connections competes with wireless devices for the ARM processors processing power. They are quite powerful for slow clocked devices, but the more they are working the slower performance will be to maintain the juggle. Example being my D-LINK Router that has a 350Mhz ARM processor in it that I flashed with DD-WRT. It sometimes is flooded with packet requests from Roku, Kindle Fire, 3 computers, Playstation 3, and Vonage VoIP Telephone, but it runs perfectly fine. HOWEVER I had to flash the $25 router to DD-WRT to gain QoS so that I could set a priority for VoIP to have an allocation of bandwidth because otherwise a download of the latest Linux Distro would cause the phone to cut out or get choppy. Setting QoS I can be downloading large files over the web and telephone acts crystal clear without issues becaue QoS rule is set to give the phone 1MB of bandwidth and leave the rest for all other devices vs all devices competing as equal priority.