IS MUSIC POETRY?

PART I

Poetry is a written form of expression; it is generally characterized by rhythmical writing, rhyme, similes, metaphors and symbolism.

For a piece if writing to be considered poetry the only requierement, I think, is for the writer to want it to be poetry.

PART II

A song that is definately not poetry would be "Closer" by Nine Inch Nails:

You let me violate you

You let me desecrate you

You let me penetrate you

You let me complicate you



Help me

I broke apart my insides

Help me

I've got no soul to sell

Help me

The only thing that works for me

Help me get away from myself



I want to fuck you like an animal

I want to feel you from the inside

I want to fuck you like an animal

My whole existence is flawed

You get me closer to god



You can have my isolation

You can have the hate that it brings

You can have my absence of faith

You can have my everything



Help me

Tear down my reason

Help me

It's your sex I can smell

Help me

You make me perfect

Help me become somebody else



I want to fuck you like an animal

I want to feel you from the inside

I want to fuck you like an animal

My whole existence is flawed

You get me closer to god



Through every forest

Above the trees

Within my stomach

Scraped off my knees

I drink the honey

Inside your hive

You are the reason

I stay alive

This song is not poetry because the writer is explicitly saying what he needs to say.  He does not want it to be nice and pretty and sound 'nice,' he just wants to send his message out.  The composer has no need to transmit a message other than what he's stating in the song and if no one else like it or doesn't understand it, too damn bad!

A song that I would consider poetry would be "Clark Gable" by The Postal Service:

I was waiting for a cross-town train in the London Underground when it struck me
That I'd been waiting since birth to find a love that would look and sound like a movie
So I changed my plans, I rented a camera and a van and then I called you
I need you to pretend that we are in love again and you agreed to

I want so badly to believe that there is truth and love is real
And I want life in every word to the extent that it's absurd

I grease the lens and frame the shot using a friend as my stand-in
The script had called for rain, but it was clear that day so we faked it
The marker snapped and I yelled, "quiet on the set!" ad then called, "action!"
I kissed you in a style Clark Gable would have admired I thought it classic

I want so badly to believe that there is truth and love is real
and I want life in every word to the extent that it's absurd
I know you're wise beyond your years but do you ever get the fear
That your perfect verse is just a lie that you tell yourself to help you get by

that you tell yourself to help you get by...
 
This song portrays life as a poem and is filled with messages of wishful thinking and hope.  The objective of the writer of this particular song may have been to leave the listener thinking-- it's the type of song that maybe someone would steal a line from and post it as their status on facebook.   The lyrics do tell a story, which would be considered prose, but in the way that the message goes out it would have to be poetic.
 
RAP and HIP-HOP
In regards to rap and hip-hop, as with any other type of music, it'd be a generalization to say that these songs are or are not poetry.  Sure, it's a cliche that these songs only make reference to sex and violence, but not all of them really do.  Every song has to be individually analyzed and detailed to interprent if indeed they are poems.
 
Songs in this genre have several literary characteristics.  The first one I'd think of is personification, especially in regards to genitalia.  
They also do have rhyme and rhythm, similes (not too many methaphors), consonance, denotation...  
 
I would certainly consider myself a context critic.  Not only for this particular musical style but for all of them, if the case be needed.  I don't like characterizations and I don't tend to be prejudiced either; every single individual piece must be selected and reviewed before a conclusion is reached.