That's misleading. It should read: 'how to capture a song'. A song is not something you manufacture, it's something that happens, sort of like a little literary fart, seeping out at the most inopportune time. Your literary fart might bubble up while you're in the bath, or driving to work, or perhaps while waking up in the morning. You'll roll over, open your eyes, and realize there's a phrase or a melody stuck in your head. The problem arises if your SO is feeling frisky that day and you get distracted. The next thing you know, your idea-fart has dissipated, leaving nothing but the faint odor of halibut.
The trick is to capture the idea-fart the moment you smell it. Maybe it's a phrase, and the phrase fits a melody. Maybe it's just a word, like 'sodomy'. Remember the Billy Joel song called 'Honesty'? It started out as 'sodomy', just like Paul McCartney's 'Yesterday' started out as 'scrambled eggs'.
(At this point, I should inform the reader that I'm pulling this stuff out of my ass, but because I'm a writer, I'm allowed to do that.)
So what do you do with that germ of an idea you woke up with (besides inserting it into your SO's favorite orifice?) The prudent thing to do would be to render the idea onto some sort of media before you forget it. For example, you could take a felt-tip pen and write it on your SO's back, or thigh, or tummy, which could be fun, but a more practical approach might be to jump out of bed, turn on your recorder, and wail away.
What if you don't have a recorder? Dumb question, dumb ass. Everyone has a recorder. If you're reading this, you have a computer, and computers have a record function that utilizes the built-in mic, you know, the one that's staring at you right now. (And by the way, would you mind getting dressed? Your minicam is on.) Most MP3 players have a voice record function. Most cell phones also have that function, although it might be called 'dictation'. (Snicker)
Another recording method is called voicemail. You call your voicemail, leave yourself a message, and then try not to erase it later when you're frantically checking to make sure you S.O. doesn't discover any remnants of that affair you had last week.
The most antiquated recording method of all would be the old-fashioned cassette deck, followed by the minidisc recorder. I have a little silver minidisc recorder with a built-in mic. It sits atop my piano, awaiting my muse like a dog awaits his daily walk. It has a large red button (the minidisc, not the dog.) You push it, and the machine starts recording - no questions asked, no menus to scroll through, no 'device not found' message flashing on the screen. Each recorded snippet is numbered on the disc, so you can go back later and catalog your ideas:
1. 'Makin' Bacon' - half-time funk (sucks)
2. 'Let's get small' - slow rock (sucks)
3. 'I could do worse than waking up with you' - fast shuffle (sucks)
... and so on down the line. My minidisc will record 160 minutes in mono, which means I can easily scroll through fifty or a hundred 'sucks' ideas before finding something worth working on.
Now, the hard part. What to do with your germ of an idea? Spray it with Bactine? That would probably be the wise choice, but for the sake of this how-to essay, let's continue.
Many times, the germ of an idea will be more like a full-blown case of the flu, with verses and choruses flowing out of you like snot. Too graphic? Okay, how about 'flowing out of you like a river rushing to the sea'? Do you see what I've done? I've illustrated one of the biggest pitfalls of writing a song - using a clichΓ© instead of something original. 'Like a river to the sea' has been done to death. It's trite. It's lame. It's the epitome of predictable. We're not trying to write Hallmark cards here, we're trying to create original art that will impress our friends, and, hopefully, get us laid. Go with the unpredictable. Surprise the listener.
So, suppose your song has already flowed out of you like snot. It's time to grab the kleenex (if there's any left after this morning, when you and your SO mussed the bed.) Just because the Muse has given you a whole mess o' words doesn't mean you have to use all of them. Just pick out the good ones. Throw the rest in the trash. This lovely little song you're working on may be your baby, but not everyone is as proud of your baby's poop as you are.
What if the germ of an idea is just a germ? You're SOL, my friend. No, not really, you just have to work a little harder. Perhaps your germ of an idea is just the tip of the iceberg. Your job is to guide the Titanic directly into the iceberg, ripping a gaping hole in the hull until the hidden meaning rises to the surface. Sometimes you'll go down with the ship, sometimes you'll see Kate Winslet, naked, reclining on a couch. It's all up to your imagination.
What if you have no imagination? Well, let's see. You could pay someone else to write your song for you, but that would defeat the purpose of this essay, so let's be creative instead. You could try free association, writing down everything you can think of that has anything to do with the poor little pitiful germ of an idea you came up with. You might fill two or three pages with ridiculous crap. This is good. This will be fuel for the fire. Or sometimes it will be fuel for the fireplace. The point is, you need raw material with which to craft your song.
This brings us to another point, and the point is: what is the point? Are your words supposed to make sense, or are you just writing for the sound of the phonetics? If it's the latter, I can't help you, because I want a song to mean something to me. I don't want to have to pick up the slack of a lazy writer, filling in the blanks left by his/her blank mind. I want the words to kick my ass. I want the words to make me laugh, or cry, or want to fuck my hot sister, or overthrow the government. I want to be moved.
A good way to do this is to treat your song as the joke that it is. LOL. Ha ha. (That came out wrong.) What I mean is, imagine you're telling a joke. The first part is the setup, the second part is the punch line. So the verse sets up the chorus, and the chorus delivers the zinger. If you give away the punch line in the verse, you have nowhere to go - you might as well just write a song that's one verse long, and then go back to watching TV, or surfing the internet, or whatever it is you do to fill the empty pages of your barren, wasted life.
Okay, so the verse is going to set up the chorus. Could we, perhaps, include a little mystery? Draw the listener in, so they are compelled to pay attention? Here's an example: