Thanks, Little Rich. Going back to when I was young, I have appreciated artists who have continued to have success as they grew older, and that's why I commented on his incredibly lengthy recording career. I figured that it had to be record-setting in some way, so it's great to see what you had to say about this. 
Another aspect of his career that I find interesting is that his signature song, "I Left My Heart in San Francisco", only reached #19 on the Hot 100 in 1962. So when I saw that Billboard had posted an article entitled "Tony Bennett’s 15 Biggest Songs on the Billboard Charts", I figured that this song was probably at the bottom of this list -- and it was.
So I was planning to post it and comment on this, but then I saw that there was something else that was directly relevant to the recent discussion here of the Top 100 vs. the Hot 100. The article states that "Tony Bennett’s biggest hits are based on peak positions, and, in the event of a tie, by weeks on the chart. For songs released before 1958, peak positions are determined by the highest position among the three major predecessor pop charts – Best Sellers in Stores, Most Played by Jukeboxes or Most Played by DJs. For songs released after 1958, peak positions are from the Billboard Hot 100, which launched on Aug. 4, 1958." In the Whitburn book that I have, which was published in 2000, he used the same basic methodogy but included the Top 100 as well for songs before Aug. 4, 1958.
So this provides some very unexpected evidence of Billboard not considering the Top 100 as a similar chart to the Hot 100, although I'm surprised that they don't take the same approach as Whitburn given that I don't think that the chart should be completely ignored. Anyway, here's the article. 
https://www.billboard.com/lists/tony-bennett-top-songs-billboard-charts/