Connecting AirPort Express to AirPort Extreme 802.11n

Question

The following steps helped me set up an AirPort Express base station connected to a set of wireless speakers with my new AirPort Extreme 802.11n base station. I’m posting this because the process was not entirely intuitive, at least not to me.
I’ll assume you have set up the AP Extreme base station to connect to the internet and run your home network and that you are connected to your wireless network.
Make sure you set-up the AP Extreme base station to broadcast in 802.11n + 802.11b/g modes, i.e. both at once. You will also have to check he setting that allows the newtork to be extended.
Reset the AP Express base station so that in runs on the factory defaults by pressing the reset button with a paper clip. Wait for it to completely restart.
Launch the AirPort Utility. You should see both your AP Extreme and AP Express base stations in the left hand column. Click on the AP Express base station you just reset. When it asks to switch wireless networks do so. Then hit continue.
On the next screen select “Connect to my current wireless network” option and hit continue.
On the following screen select the “Extend the range of my AirPort Extreme or AirPort Express network” and hit continue. Do NOT select the “Join my wireless network” option even though it says this is how you connect to wireless speakers. This is the part that was not obvious to me. When I tried this the AirPort Express base station flashed orange and wouldn’t connect despite waiting 30 minutes.
Chose the network you wish to extend from the drop down menu. My keychain supplied the password for the network.
Give your base station a name and hit continue.
Select the main base station in the list provided. This is the one connected to the internet and hit ok.
The Airport Utility software will configure the network to accept the AirPort Express base station.
Now all that’s left is to connect your wireless speakers to the AirPort Exppress base station. You can now play music through AirTunes while being connected to your fast 802.11n network.

Answer 1

I recently setup an Airport Express in conjuction with my Extreme Base Station. I'm not really understanding how this method enables 802.11n connection speeds (via Base Station) to the internet and also allow streaming music through the Express at 802.11b/g. It's my understanding that if you want to be able to access the internet AND stream music at the same time the Express needs to join the network. In order for the Express to join the network (able to recognize the Base Station)...the Base station needs to be changed from 802.11n only to 802.11n (802.11b/g compatable)....which essentially means your connecting to the internet at 802.11b/g. If your wanting to keep 802.11n only on the base station...you would have to create a seperate network via the Express to stream music. What this means is you CANNOT access the internet and stream music at the same time. You would have to manually change Airport in the taskbar to do one or the other.
Am I off base here? If I am missing something please let me know...because it would be great to be able to connect to the internet at 802.11n only with a multi-case rate set to 23Mbps vs. the 11Mbps (maximum) of the 802.11b/g compatable option.
I guess what is confusing me is that my setup is basically the same as what was described above..minus having the "Extended Network" being enabled. How does extending the network change things?