Stuttering is often a network issue, I used to have it with a single Airport Express, and interference from cordless landline phones, microwaves etc can affect things as can competing neighbouring networks - worth changing wi-fi channels if you haven't done so.
Music itself should not require huge bandwidth but with multiple devices connecting wi-fi can struggle.
Is your Macbook wired or wi-fi? If wi-fi try connecting it wired to the Extreme to see if that helps.
I'm not a big fan of wi-fi stability and for many things have swapped to mains powerline network adapters such as those made by Devolo.
Are your Express units old b/g ones or newer n ones.
Also if you go into Airport Utility for the Extreme, Advanced tabs, logs and statistics and choose wireless clients it should give an idea of speeds of connected wireless devices including the airports.
Thanks for the info.
But here there is more than meets the eye here.
My MacBook is connected to the Network wirelessly.
When I use the iBook it is also connected wirelessly.
When I use the iBook with OS 10.4.11 and iTunes 8.2 the music runs fairly flawlessly most of the time.
The Extreme is one of the previous generation b/g/n units.
Two of the three Expresses are the b/g/n devices and the third is a b/g unit.
The confusing thing is that the iBook has no problems, so I infer that it may not be a network problem, unless the 2003 iBook has better WiFi connectivity than my 2009 MacBook.
There are several things that I plan to try, among them are:
1. Connec the MacBook directly to the Extreme. If this solves the problem, maybe it is a signal strength issue.
2. If signal strength is an issue, I have another AE that I use for travel, I can set it up as a network client and connect it to the MacBook to see if it will provide better connectivity than just the MacBook.
I put the MacBook on the same table as the AirPort Extreme used to create the wireless Music network, allowed wireless connection and it appears to be working.
It just did not make sense to me that a 2003 iBook G4 could have better wifi connectivity than a 2009 MacBook.
Anyway, since my wife would never go for leaving a computer in the living room, no matter what the function (a computer just does not appeal to her decorating ascetics in the living room, well, mine neither)
So I guess I'll change the settings on the Airport Extreme to WDS, set up an AX (Airport Express) in my office to participate in the network and hopefully the signal will be better for the AX than to the MacBook, and the the MacBook should connect to the AX and work!
Thanks AC for pushing me to try the network more before I got more involved in changing the OS and hunting for older versions of iTunes.