Spring

Sound the Flute!
Now it's mute.
Birds delight
Day and Night;
Nightingale
In the dale,
Lark in Sky,
Merrily,
Merrily, Merrily, to welcome in the Year.

Little Boy,
Full of joy;
Little Girl,
Sweet and small;
Cock does crow,
So do you;
Merry voice,
Infant noise,

Merrily, Merrily, to welcome in the Year.
Little Lamb,
Here I am;
Come and lick
My white neck;
Let me pull
Your soft Wool;
Let me kiss
Your soft face:
Merrily, Merrily, we welcome in the Year.

Commentary by Jeff Gillett

In this song, a world of new life is inhabited by children and lambs, which are seen as joyful, playful and essentially innocent. The flute in the first line leads us back to the piper/poet in the Introduction to the Songs of Innocence, and the reference in that poem to 'a song about a lamb' helps to make Introduction, The Lamb and Spring a tightly inter-linked little triangle of poems.  It isn't clear why the flute is 'mute' in the second line: perhaps because it is representative of Spring, and has therefore been silent through Winter.

This is another poem of child-like joy and exuberance, drawing parallels with The Ecchoing Green, Nurse's Song from Innocence, Laughing Song and the opening stanza of The School Boy. As such, it repeats succinctly images of nightingale and lark singing, along with the cock crowing. 'Merry' and 'merrily' are repeated, and in this context, even the 'Infant noise' has positive connotations.

The second stanza's words addressed to a 'Little boy' and 'Little girl', not to mention that  reference to 'infant noise', might lead you to hear an adult voice in this poem. However, since the hugging, stroking and mutual licking and kissing with the lamb in the last stanza does not really seem like adult behaviour (quite apart from the fact that it is not to be recommended on grounds of health and hygiene), it appears that the speaker may also be a child. Nevertheless, Blake was writing this poem as an adult himself and may simply have been attempting to capture a sense of innocent elation.