A New Twist on an Old Cipher

Question

Presenting a modern cipher —
Like many new cars, and unlike Vigenére, it is keyless.
No quaint, old-timey little Dancing Men or Pigpen symbols.
Nothing so convoluted as PlayFair or Enigma.
No, it's something simple but novel, like a more progressive Caesar.
I'm confident you'll be able to figure it out!

At ca pqy aqw eohduob kdg xs
Rsxmgi mtb ymnx "hnumjw" ltjx
Xjjrx ny'x ynrj kux se tkdz ingrrktml —
Dpss fvb zapss il vu fvby avlz?

Lupnthapj wbggslz jhu il
Ylhssf mbu... Dpss fvb ahrl svun, av
Mpuk aom Icbpwz wn ug Abwzg?
Wz bpm Aqwpna xo vh Bxwp?

Dbn cqn ludnb cqrb aqhvn prenb cx hxd,
Wx wnnm cx secd dkup l rfpdd
Opqtytepwk ruzp ftq axpqef
Uf'e ftq azq U yhfg fhttrfg!

Asjsf hvwby hvwg fvmas wg igszsgg
Zwbs pm zwbs wh wg mcjg vjxst
Xih bpe ev uglzmrcvetzvj
Efn r jvtiwl oadd mfzavw!

Wfvdwkl tl t yetpexll vbkvex?
Xgwexll tl mby Oidqanoa?
Eo pda wjosbo vlr'sb burpyarcb
Emgle rm msrjgtc rfgq tcpqc?

Fmnc wnt mnv jmnv vgzs lx mzld hr —
Sgdqd hr fnhmf sn ad z pthy!

Oh, you'll need this:

1 11 19 1 21 17   1 13 1   3 14 16 2 18 2 16

Your final answer is a person's name.
Who is it?

Answer 1

Mike Limburg and Techidiout have already found out how to decode the message:

The message is a Caesar cipher whose shift varies. It starts with a shift of zero. When the encoded letter corresponds to the shift – where A corresponds to 0, B to 1, C to 2 and Z to 25 — the shift increases. (That's why the last letters in stretches of material that was decoded with the same shift end with all the letters of the alphabet in order.)

Here's the decoded poem with line numbers. The changes of Caesar shift are indicated with vertical bars:

   1   A |s b |y now you c |learly had | to
   2   Notice | how this "cipher" goes
   3   Seems it's time f |or my next challeng |e -
   4   Will you still be on your toes?

   5   Enigmatic puzzles can be
   6   Really fun... Will you take long, to
   7   Find th |e Author of my Story?
   8   Or the Si |nger of my Song?

   9   Use the clues this rhyme gives to you,
  10   No need to j |ust tak |e a guess
  11   Definitel |y find the oldest
  12   It's the one I m |ust suggest!

  13   N |ever think this rhyme is useless
  14   Line by line it is yo |ur guide
  15   Its map | of eq |uivalencies
  16   Now a secr |et will unhide!

  17   Endles |s as a flawless circle?
  18   Endless as t |he U |niv |erse?
  19   Is the answ |er you've ex |tracted
  20   Going to outlive this verse?

  21   Hope y |ou now know what my name is -
  22   There is going to be a quiz |!

Now we must decode the list of numbers with a cipher hidden in the poem.

The poem says that the rhyme will be our guide "line for line". It associates lines of the poem with the last letters before the change of the shift. A line can have no, one or several letters associated. For example, 1 may refer to a,b,c or d; 2 uniquely refers to e; 4 doesn't refer to anything. (This skew relationship makes it impossible to use cryptogram solvers.)

Applying this to the numbers

   1 11 19 1 21 17   1 13 1   3 14 16 2 18 2 16

yields:

   abcd·l·wx·abcd·y·s   abcd·n·abcd   fg·o·r·e·tuv·e·r

and, after selecting the appropriate letters from the lines with multiple options:

  Always And Forever

Another thing Mike and Techidiot have found out is ...

... that the first letters of each line in the decoded poem read:

   Answer found in line eight!

Line 8 of the poem is:

   Or the Singer of my Song?

There are others songs, music albums and films with the title Always and forever, but the poem says that we need the "oldest".

So the final answer may be:

Johnnie Wilder Jr., who was the lead singer of the band Heatwave, when the song Always and Forever was first recorded for their album Too Hot to Handle in 1976.

Answer 2

[Very Partial]

We can translate the whole text using different ROT-X's. Starting at ROT26 (normal text) from the top of the text:

Rot26: A
Rot25: s b
Rot24: y now you c
Rot23: learly had
Rot22: to notice
Rot21: how this "cipher" goes Seems it's time f
Rot20: or my next challeng
Rot19: e —Will you still be on your toes? Enigmatic puzzles can be Really fun... Will you take long, to Find th
Rot18: e Author of my Story? Or the Si
Rot17: nger of my Song? Use the clues this rhyme gives to you, No need to j
Rot16: ust tak
Rot15: e a guess Definitel
Rot14: y find the oldest It's the one I m
Rot13: ust suggest! N
Rot12: ever think this rhyme is useless Line by line it is yo
Rot11: ur guide Its map
Rot10: of eq
Rot09: uivalencies Now a secr
Rot08: et will unhide! Endles
Rot07: s as a flawless circle? Endless as t
Rot06: he U
Rot05: niv
Rot04: erse? Is the answ
Rot03: er you've ex
Rot02: tracted Going to outlive this verse? Hope y
Rot01: ou now know what my name is — There is going to be a quiz!

Final story is:

As by now you clearly had to
notice how this "cipher" goes
Seems it's time for my next challenge —
Will you still be on your toes?
Enigmatic puzzles can be
Really fun... Will you take long, to
Find the Author of my Story?
Or the Singer of my Song?
Use the clues this rhyme gives to you,
No need to just take a guess
Definitely find the oldest
It's the one I must suggest!
Never think this rhyme is useless
Line by line it is your guide
Its map of equivalencies
Now a secret will unhide!
Endless as a flawless circle?
Endless as the Universe?
Is the answer you've extracted
going to outlive this verse?
Hope you now know what my name is —
There is going to be a quiz!

As @TechIdiot found out, the first characters spell out:

Answer found in line eight, which is;
Or the Singer of my Song?

And, as @Totumus Maximus discovered:

All ROT-X's endings are the characters of the alphabet, in chrononogical order.

Are we looking for a singer's name, particular who song "My Song?" Then the answer will be:

Alessia Cara

However, we don't use the numbers there. I tried playing, converting the numbers into letters from the alphabet and the first letters from line 8, ending emptyhanded.

Answer 3

Here's the final rhyme -

Just keep doing rot-n(1,2,3...) starting from bottom to top and forming the rhyme...


As by now you clearly had to
Notice how this "cipher" goes
Seems it's time for my next challenge —
Will you still be on your toes?

Enigmatic puzzles can be
Really fun... Will you take long, to
Find the Author of my Story?
Or the Singer of my Song?

Use the clues this rhyme gives to you,
No need to just take a guess
Definitely find the oldest
It's the one I must suggest!

Never think this rhyme is useless
Line by line it is your guide
Its map of equivalencies
Now a secret will unhide!

Endless as a flawless circle?
Endless as the Universe?
Is the answer you've extracted
Going to outlive this verse?

Hope you now know what my name is —
There is going to be a quiz!


The first letters of the rhyme say -
ANSWER FOUND IN LINE EIGHT!

Or the Singer of my Song? is the 8th line here -

Utilizing the numbers and using them as index to this line doesn't lead to anything meaningful yet. May be they are again rot-n indexes...