A Code That's a Little Bit Weird

Question

The street outside Rockefeller Center was a very busy place to hide a secret message, I thought, but sometimes the best place to hide something was in plain sight. I'm a government agent, from one of those alphabet agencies, investigating corruption in international song competitions. I was going to meet an unknown contact for information, but first I had been told to find a message here.

The note I had to find was taped to the bottom of a park bench; standard stuff, really. I recovered the note and opened it to find the following handwritten message.

WHERE ARE YOU?

← → ← →

DMUQBAA ZPBLKBKL: KJEOQDMYB

KEEP MOVING!

I obeyed the final message, walking to meet up with my contact in a bar nearby. But I didn't know anything about them! Perhaps the cyphertext would give me information, or at let me know who I was looking for.

What does the message say?

Answer 1

The message says:

CONTACT CODENAME: NIGHTCORE

Method:

Split the ciphertext into groups of 4 letters. For every group, shift the first letter alphabetically to the left by 1, the second letter to the right by 2, third letter to the left by 7 and fourth letter to the right by 3 (directions indicated by the arrows in the note)

(This is equivalent to a Vigenere cipher with the key 'BYHX')

Why:

There are multiple references to the Eurovision Song Contest in this puzzle: E.g. "international song competition", "WHERE ARE YOU?" and most notably "Rockefeller Center", "Keep moving" and "A little bit weird", which is a reference to the song Rockefeller Street, which was also part of the ESC in 2011 ("Keep moving" and "a little bit weird" are part of the lyrics)

The chorus of the song features the line "1273, down the Rockefeller street", which, combined with the arrows, is the key for the cipher.

Nightcore versions of this song are especially popular.