Airport Express Appears Connected, But No Music

Question

I have the oldest version of Airport Express, and a 2009 vintage Macbook Pro with Yosemite recently installed, iTunes 12.0.0.140. Yosemite does not support the Airport Utility needed for the AE I have, but I was able to configure using Airport Utility 5.6.1 launcher from Corey Mahler.  So, the light is green on the AE, and iTunes shows clean connection to the AE, but there is no sound.  I have checked the connection from the AE to the receiver, and from receiver to speakers.
Prior to upgrading to Yosemite I was on Snow Leopard, the AE worked OK, except it tended to drop out and then only work intermittently the longer it was in use in any given session. But at least then I knew I had a connection.  Now with Yosemite and latest iTunes I'm wondering whether something else is preventing the music from playing.  Would think that iTunes would flag this if that were the case.
Any ideas?
Thanks in advance.

Answer 1

You are correct on all counts.
I have a fairly new Linksys 6200 main router which does provide dual band Wi-Fi.
Since last writing, I did follow your recommendation to purchase and download Wi-Fi Explorer.  It gave me an excellent graphical view of the strengths of the various Wi-Fi networks, and I did confirm that my network was putting out the dual bands, that my extender was also putting out, etc.  I could also walk around the house and see how the signals rose and fell, depending on location.
Signal seems to be strong enough in all areas that the airport express should work, however it only seems to work, and then just intermittently, when I have it close to the main router, where the signal strength according to Wi-Fi Explorer reads 84%. If I move my laptop to the AE's original location, the signal is about 68%, and is coming via the extender. Most of the neighbors' signals were below 50%, but there are a lot of them.  Too bad the AE does not supper 5GHz bands because they seem wide open except for my router.
Not sure how the signal strength % relates to signal to noise ratio.
What I could also see is that the 2.4GHz band where most of the neighborhood networks were broadcasting. I tried to assign my main router to specific bands (only choice is within the 2.4GHz for the AE), instead of automatic, and sometimes it helped when the AE was close to the router, but it would still cut out.
So, when the AE is close to the router, I get some intermittent sound, but further away, nothing at all. So it appears that there is something either wrong with the AE or its just not getting the quality of signal it needs from the newer routers.
Our iPads, iphones, Apple TV seem to work fine - though the Apple TV occasionally pauses to re-load.
The variables over the last few months have been:
1. The newer Linksys main router, which replaced another older Linksys (both cases used default settings except for network access password).
2. A Linksys extender added recently so that my son could use his "smart" TV.
3. My upgrading from Snow Leopard to Yosemite two weeks ago (on 10.10.1 now).
Prior to these, the AE would sometimes go for hours without a problem, but then stop playing for seconds or minutes (green light on regardless). It was when I installed Yosemite that I lost even intermittent sound coming from the AE, in its original location.
I am tempted to try a newer AE to see whether access to the 5GHz band would solve the problem.
Thanks again.