What is "concertize"

Usage examples of "concertize".

And then, after a few years' absence from the intoxication of applause, had returned and concertized more actively than ever.

Beauty of music -- so wondrous in its effect when discreetly used, but which could so easily slide over the brink into what Allchin might call concertizing, to ravishing the spirit with sweet sounds which were loved for themselves and not as adjuncts to prayer and proper devotion.