Who are some acts/artists who have had wildly successful careers in music while largely flying under the radar? For example, they never really had any actual radio hits and are seemingly not referenced very frequently.

^^^ To me, the list that you are wanting here is endless and it is because it all depends on what is considered success, and at the end of the day everyone is going to have their own opinion on such a subject.

God bless you and my number one pick always!!!

Holly (a girl who only loves Mason Ramsey even more every day)

P.S. Since I do mention a singer here, I will go ahead and talk about what they have accomplished so far. Mason was on the Ellen DeGeneres talk show four times, he took the stage during the 2018 Coachella gathering when he was just eleven years old, he sang during one of the Stagecoach gatherings, he was on the Grammy awards show stage in early 2020, he's been on the Grand Ole Opry stage at least six times, he was in Europe a year ago for the Country 2 Country gathering, and then if you go to this clip here (https://www.youtube.com/watch?v=nsPAfRrAXaM), you can see him receive a plaque for what could be his only gold single at the moment. It was given to him just days before his 14th birthday which was on November 16, 2020. :) :) :)

Deep Purple never had a #1 hit single on the Billboard 100. They had 2 songs which reached #4 (“Hush” and “Smoke on the Water”).