You have to consider this about that ONE HIT & why it is difficult to replicate. Generally the writer has had a lifetime (long or short) to come up with their initial "Hit". So you may have to write 50-100-300 songs to get that ONE SONG that stands out.

But of course we expect the next tune to surpass the last one.

It doesn't generally work that way. I just wrote possibly my best tune "First Love, Last Love" 2 months ago since my first song written in 1981. It took me 38 years to get to that tune

Steve Altonian---"I'll just do my best & let God do the rest"

http://www.stevealtonian.com