James Boyk wrote:

Any suggestions for how I can fly (right now or at any time) from Los
Angeles to Europe for concert bookings---or to the Eastern U.S., for
that matter---given that I don't fit in economy-class seats and can't
afford 1st-class?

Presumably you have looked into international business class? It's cheaper than
first, provides wider seats and more legrrom in the international leg, and a
domestic first class seat.