Zhècì yīnyuèhuì huìjí le quánqiú zuì dǐngjiān de yìshùjiā, kānchēng kōngqiánjuéhòu.
This concert brought together the world's finest artists — truly unprecedented and unrepeatable.
Tips
memory
空前 = nothing came before (空 = empty, 前 = before), 绝后 = nothing will come after (绝 = cut off, 后 = after) → there was nothing before it and will be nothing after it.
usage
空前绝后 is often used with admiration, but can also be used ironically to describe something spectacularly bad. Compare with 前所未有 (qián suǒ wèi yǒu), which means 'unprecedented' but doesn't imply it can't be repeated.
