Guitar Hero 5

This guide should allow you to unlock "Score Biggest," "Score Bigger," and "The Streak" in one play.

I uploaded my own song, called "Score Big w star". The ones I was looking at didn't have Star Power in the songs, so I figured that was just wasting notes. Might as well get the 8x multiplier as well for extra points. I also used two sustained notes (green-red) instead of one.

I did this because I was having issues with Score Biggest, even using some of the songs on GHTunes, especially since a missed note or two meant that I wouldn't hit 3M even after 10 minutes. (Twice I got around 2.7M because I missed a single note.)

Same as other suggestions: one guitar, one drum. Set the drum up on auto kick. Play the guitar, and strum. Use Star Power as you see fit while the auto drum goes crazy.

It's 7:16 in length, so it isn't as long as some others, but you should probably get 3 million at about 5:50. Along the way, the drummer should get "The Streak" if they don't already have it (there are over 6500 drum kicks), so if you're doing this solo, log in on the drums and use the guitar as a 2nd account.

You can also make your own song, as others have suggested. That way you get the "Producer" achievement as well, like I did. :-) You don't have to use it, but I figured since I'd already made it, might as well post it. If it helps you, enjoy.

If you have two mics you can get this very easily using the fan trick. Setup both mics on expert and you can even play guitar on medium. Do this on the song Bring the Noize 20xx

To get this achievement I made a 200 measure song, which is about 7 minutes. if you have a guitar keep playing a 4 note chord, when I completed the song by myself I got 1,076,560 points, since what you make is the exppert diffuculty, make sure you put the difuculty as expert when you play it

I did this with a random guy online, he was playing expert guitar and I was playing expert bass. I chose "Medicate" by AFI. The reasons being because it is easy on expert bass.
If you use this method, you will need to hit a decent percentage of the notes, both me and the guitarist hit 98% and had over 1million points, my advice for this song is alt strumming (Moving strum bar up and down). It is an easy strumming pattern figure out.

Got this on the Peter Frampton song. My buddy was on Expert Guitar and I was on Hard Bass. We got 1,600,000 points. It is super long so you should be able to get over 1 million without much trouble.

I saw this listed as a solution to 500,000 as a solo act, but it also works for this achievement.

go to ghtunes and type score big 1 mill. download that and play it on expert+ drums with the auto-kick cheat enabled. All the notes are kicks, so you don't even have to do anything but watch. And the kicks are really close together, so the song isn't even that long.

Using this method, I unlocked both the "Score Big" and "Score Bigger" achievements after 1 play through.