Elvis lets regulars sing merrily (4)

I believe the answer is:

lilt

I'm a little stuck... Click here to teach me more about this clue!

'sing merrily' is the definition.
'lilt' can be an answer for 'sing' (thesaurus). I am not certain of the 'merrily' bit.

'elvis lets regulars' is the wordplay.
'regulars' means one should take alternating letters (letters selected at regular intervals).
'elvis'+'lets'='elvislets'
The alternating letters of 'elvislets' are 'LILT'.

Can you help me to learn more?

(Other definitions for lilt that I've seen before include "Rising and falling of the voice in speech" , "Swing - rhythm" , "Pleasant gentle accent" , "Light graceful swinging rhythm" , "Till to get light and pleasant rhythm" .)

I've seen this clue in The Irish Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.