I had a question regarding this paragraph... not sure where "concert A" is coming from.
I'm not sure if this answers your question, but concert A (A in the 4th octave on a piano) is the standard for tuning across most concert bands and orchestras. but that frequency of what Concert A meant used to vary from region to region. Adam Neely has an amazing video on the history of that when he made a video debunking the myths surrounding A = 432Hz.