Complex sentence: In both years the great majority of their recordings featured a wide variety of horns, often in multiples, piano, and other instruments, but the all-string instrumentation is the one most often adopted by emulators of the Hot Club sound.
Split into simpler sentences: In both years, it should be noted, the great majority of their recordings featured a wide variety of horns, often in multiples, piano, and other instruments. But, the all-string format is the one most often adopted by emulators of the Hot Club sound.