Can I draw 2 cards with Sam if I reveal Raven´s song?

(I can´t find if reveal a plot is considered to be to play a plot or not, so it triggers Sam´s response)

No you can't. Revealing a plot doesn't count as being played. Only attachments, characters, events, and locations can be played. Also note that Sam can't trigger off of a raven card being "put into play" either. For him to work, you have to pay the cost of the raven card and play it from your hand.