Absolutely unable to solve the cipher

[btcdragonlord]

This is just tooo much for me, been sitting at it for over 9 hours and I can't figure it out.

This is even more worse because on easy difficulty this is already given and there are no hints in the text, like make it exceptionally hard to figure out.

POLYCHROMATIC WATERSCAPES
SERVANT DANCE
OMNIPRESENT PRESSURE
MAIL FROM A WORLD GONE BY

This was the interval keys

Interval key: minor sixth, perfect unison, major seventh.

Octave keys:

Key 1: 360664134766374373747733647
Key ?: 360747736733634
Key ?: 3 606664674746767477774
Key ?: 36063444766376743466431::

And here is the note:
Here's your text:
BBbGGBbD#DbBbG#G#D#EBb F#G#D#CDbDBbG#BCD
DCDbFG#AD#BG#ABbC
BbG#AEBDbCDCAD# BDbCDDEDbC
G#G#EG DbDbBbG# G# F#BbDbGB DBbAC AG

::::And here's the keypad code:
BbF#BF

And since the keypad code is already given, I still unable to figure this out.

[Corado]

1928 ??

wtf  WHAT IS world's tallest tree specie?

[WeiJayTan]

The code is 1928. Let me know whether it works or not.

Minor 6th (8 Semitones)
Perfect Unison (0 semitones)
Major 7th (11 semitones)

Following the information given, the decoding table should be as follows:

A    B  C    D  E  F    G   H   I  J  K   L  [Octave numbers 3,4 assigned to musical notes] [Block 1] [Original shifted by 8 Semitones] [8]
G#  A  A# B  C  C# D  D#  E F  F# G

M   N O   P Q  R  S  T   U V W  X [Octave numbers 6, 7 assigned to musical notes] [Block 2] [Original shifted by 8 semitones] [8+0]
G# A A# B C C# D D# E F F# G

Y  Z   0   1   2 3  4   5  6   7  8   9  [...] [Block 3] [Original shifted by 19 semitones] [8+11]
G G# A  A# B C C# D D# E  F  F#

Note: C#=Db, D#=Eb, F#=Gb, G#=Ab, A#=Bb

I decoded the first line of the text, and it indeed reads 'Polychromatic Waterscapes', but unlike normal or hard difficulty that of which I have experienced, there is no number hidden within the text.

The given keypad code (Encrypted) is
BbF#BF

So, following block 3, it decodes to: 1 9 2 8.