Sincerely, a song originally written and performed by the Moonglows who took it to number one, was soon covered by the McGuire Sisters and many years later by the Forester Sisters and later still by Barry Manilow and Phyllis McGuire. Out of all the versions, while all quite good, there is just something about the McGuire Sisters that leaps a wee bit ahead of the pack as the best of the bunch.