As usual Angry Bird's Nest has a guide
Golden Egg #4 is unlocked when you obtain 3 stars on all levels of Poached Eggs. The Angry Birds Soundboard is the first of the puzzle levels. Here’s what you need to do to unlock the star. Press the group of birds, slingshot, TNT, any top bird, and finally any bottom pig.
There's also two similar levels you could be referring to:
Golden Egg #12 is unlocked when you obtain 3 stars on all levels of Danger Above. The second soundboard puzzle level is all about the birds and their beautiful harmonies. To get the star press blue bird, red bird, black bird (with eyes closed), blue bird, then finally the green bird.
Golden Egg #17 is unlocked when you obtain 3 stars on all levels of The Big Setup. To get the star first fill in all the pigs then tap Big Brother so he opens his eyes. Now drag him to all the way to the right.
No. 17 was originally broken on the Android version, I believe, but doing the above has worked for a while now.