How about this,
Note: While there can be many requirements to define a hit, at the minimum charting in Top 20 of the Circle Digital Charts is needed.
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Tier S: Acts which in the past and still are consistently delivering hits, with each comeback doing as well or better than the previous.
Tier A: Acts whose recent 2 comebacks have been hits or debuts have been hits, but not so in the past, which have hits & misses..
Tier B: Acts which have hits in the past, but whose most recent 2 comebacks have not been a hit
Tier C: Acts which have some fame of any sort and any name recognition, viral moments etc., Songs which charted in Top 100.
Tier D: Acts which have little to no recognition, no song in the Top 100.
Thoughts?