If the T41 Laptop connects to the internet "wirelessly" and its wired ethernet adapter is not currently used, you can enable "Internet Connection Sharing" on the Wireless Network Connection. Your wired music network could then connect to the ethernet adapter for internet access.
When you do this, the T41 Laptop's "wired" ethernet adapter will be given the IP address 192.168.0.1 by Windows and will act as the DHCP server to allocate IP addresses to the connected devices.
From your other thread, I see that your router operates in the 192.168.0.0 Subnet, so this will have to be changed to avoid a conflict as Internet Connection Sharing must use this range. You need to change the third octet (number) of your router's own IP address from "0" to say 1 or 2. Computers getting their addresses automatically will continue to do so, but the one you've manually configured would have to have its third octet changed too. Any firewall configuration that uses IP addresses will need to be reconfigured.