The successor of the king's comeback single was released on July 5, 1960. "It's Now Or Never" entered the "Hot 100" on the 18th of the month at number 44, had a run of 20 weeks and peaked at number 1. "A Mess Of Blues" followed on the 25th, stayed for 11 weeks and made it to number 32. The RIAA honored the domestic sales with Gold (1983) and Platinum (1992). In Great Britain the single also became a number one hit. When BMG re-released all of the king's UK chart toppers in 2005, "It's Now Or Never" once again peaked at the number 1. Worldwide "It's Now Or Never" / "A Mess Of Blues" sold 28 million copies and became the most successful single release of the 1960s. With "Don't Be Cruel" / "Hound Dog" being the most successful single release of the 1950s, Elvis Presley is the only artist so far, who managed to release the best selling singles of two decades. By the way: The amount of physical sales translates to 4.2 billion paid streams! However, over the decades "It's Now Or Never" seems to have lost some of its appeal. At a tad below 100 million streams it barely made it on Spotify's top 20 of the most streamed Presley songs. Of course it's still a very popular track since "A Mess Of Blues" accumulates just 10% of this amount.

The picture on the sleeve was shot during a press conference at the Graceland property. It's one of the few record covers, that show the king with his natural hair color.

The single is not available on the streaming platforms, but "It's Now Or Never" can be found on "Elvis' Golden Records - Volume 3" (1963) and "A Mess Of Blues" is included on "Elvis' Gold Records - Volume 4" (1968).

In 1898 the Neapolitan singer and musician Eduardo Di Capua wrote "O Sole Mio" ("My Sun") and used the lyrics of the poet Giovanni Capurro. Even though the song became very popular, both parties died without any assets. At the time there were no royalties for writers and so the men sold the song for 25 lira to the publishing company of Ferdinando Bideri. Many years later the heirs of Emanuele Alfredo Mazzucci sued the publisher for royalties, because he had written down the notes of "O Sole Mio". Since they won the lawsuit they receive a whopping 250,000 USD per year. The first known recording of "O Sole Mio" was made in 1901 by Francisco Daddi. Eleven years later Elisabeth Spencer released an English version named "Your Own Dear Kiss". Elvis got to know the song in form of another English edition called "There's No Tomorrow". He wanted to record it, but because the melody by now was in public domain, Aaron Schroeder and Wally Gold wrote new lyrics and legally created a new song, that could be published on its own. Elvis recorded it on April 3, 1960 at RCA Studio B in Nashville/Tennessee. The master is a splice of the takes 4 and 2, on April 5th piano and percussion was added. RCA re-released "It's Now Or Never" on the extended player "Elvis By Request" (1961), on the albums "Elvis' Golden Records - Volume 3" (1963) and "A Legendary Performer - Volume 2" (1976) and the boxed set "Worldwide 50 Gold Records - Volume 1" (1970). A live version can be found on "Elvis In Concert" (1977).

The uptempo song was written by Doc Pomus and Mort Shuman and also could have been the a-side of a single. Elvis taped it within five takes on March 20, 1960 at RCA Studio B in Nashville/Tennessee. RCA Victor later also released "A Mess Of Blues" on the longplayer "Elvis' Gold Records - Volume 4" and on the boxed set "Worldwide 50 Gold Award Hits - Volume 1" (1970).