Listen to Sincerely online. Sincerely is an English language song and is sung by The Moonglows. Sincerely, from the album The Rebellious Jukebox Plays Doo-Wop Daddies (Volume 2 - The Aching Ballads), was released in the year 2014. The duration of the song is 3:12. Download English songs online from JioSaavn.