Despite the discussion above I can't find the whole song in Mudcat.
So here is how it appears in "Singing Together".

________________

NOW IS THE MONTH OF MAYING
Ballet by Thomas Morley (1595)

1,Now is the month of maying,
When merry lads are playing,
Fa la la la la la la la la
Fa la la la la la la.
Each with his bonny lass,
A- dancing on the grass.
Fa la la la la
Fa la la la la la la,
Fa la la la la

2,The Spring, clad all in gladness,
Doth laugh at Winter’s sadness,
Fa la la la la la la la la
Fa la la la la la la.
And to the bagpipe’s sound,
The nymphs tread out their ground.
Fa la la la la
Fa la la la la la la,
Fa la la la la

3,Fye then, why sit we musing,
Sweet youth’s delights refusing?
Fa la la la la la la la la
Fa la la la la la la.
Say, dainty nymphs, and speak,
Shall we play barley-break?
Fa la la la la
Fa la la la la la la,
Fa la la la la

X: 1
T:Month of maying
M:4/4
L:1/4
S: Singing Together Summer 1953
Z: NP 21 March 2021
K:G
||G | GGAA| B2BG | B3/ A/ B^c | d2d A/B/ | ccBG | AFDd/c/ | BcAA | G2z| B| Add^c| d3 A| ccBB| A2zd/c/| BGd2| D/E/ F/G/ A/B/ c| B3/ c/ BA| G2z||
w: 1,Now is the month of may-ing, When mer-ry lads are play-ing, Fa la la la la la la la la Fa la la la la la la. Each with his bon-ny lass, A- danc-ing on the grass. Fa la la la la Fa la la la la la la, Fa la la la la


Sourced from "Singing Together" Summer Term 1953, from the BBC Broadcasts for Schools series. Noted there as From 'The National Song Book' (Boosey & Hawkes Ltd)
As ever, the tune may be seen as a PDF, or heard as a Midi by copying the above (from 'X:1' to the final 'la') into an ABC converter such as the one at Mandolintab
The last line of the first verse 'a-dancing on the grass' appears in other sources as "Upon the greening (or greeny) grass".
Singing Together also advises that A Ballet was an Elizabethan part-song with a 'Fa-la-la' chorus. The final 't' is pronounced
NP