How popular was the song of a Lonely from band Yes?

The song you're referring to is "Roundabout" by the band Yes, not "A Lonely." "Roundabout" was extremely popular and was released as a single in 1971. It gained significant airplay and became one of Yes' most well-known and successful songs. As a result, "Roundabout" became one of the band's most iconic songs and still remains popular today.