Graham, I have to say that I for one do not know., but would say that logic (or at least my perspective of logic) suggests to me that they would have used the existing arrangements that were familiar to both Bing and the sisters. Why "reinvent the wheel" which in this case would have meant new arrangements for all to learn and rehearse, plus the danger of possible errors in performances, broadcast live, because of deviation from the familiar. Given the working relationship with Schoen I don't suppose he would object.  

The specific dates of 1944 and 1948 (unless a range covering those dates was intended) do open another line of thought though. I do not think that the sisters appeared with Bing on his KMH show in 1944 nor with him in 1948 on Philco. They did appear on the shows in other years, but in those specific years the joint appearances were on forces shows where the accompanying orchestra might not have been Trotter's but such as Meredith Willson. However, I think the same logic would apply! 

Can anyone comment from an informed perspective? This is just the type of discussion which could further our knowledge and appreciation of the artistic legacy of all the artists concerned.


  

John Funnell has advised me that the tracks he played are from a package SWINGIN' WITH BING: BING CROSBY'S LOST RADIO RECORDINGS produced and compiled by Ken Barnes and the accompanying booklet says they are from Philco shows with JST's orchestra.