The words, "amazing talent," isn't used lightly. The four brothers began performing in 1928. And here they are -- three of them, at least, still performing (and doing it magnificently) in 1981. This performance was at Tivoli Gardens, in Copenhangen. A mere 53 years after they began.
By the way, any group sticking together for 53 years is remarkable. Just staying friends with someone for 53 years is impressive. But to stick together performing for 53 years and still be this good, sounding almost the same, is borderline incomprehensible.