Rock Band 3

This is really easy even if you have no idea how to play Keys.

1) Need You Tonight: A single three-note chord repeated about 20 times.

2) Whip It: Two easy patterns repeated a few times and a third easy pattern that appears once.

3) Rainbow in the Dark: A single repeating pattern on Yellow and Blue. It appears during choruses maybe four times in the song. Put your left fingers on the yellow keys and your right index, middle, and ring fingers on the blue keys. The pattern appears right at the beginning of the song so start over a few times until you get the hang of it.

The only thing I can add to Sully's method which helped me out greatly is to spam Rainbow in the Dark. Since there are no chords, just spam all the buttons the song plays really fast and you'll hit them all and get 100% by the end of the song. It doesn't matter if you keep hearing and seeing misses, you are obviously still hitting the notes. To make sure you are, be in the challenge so you can see your %. This song gave me some trouble compared to the first two.

Just to add on to the guides above. If you have a few extra points, I would recommend buying the song Helen Wheels by Paul McCartney & Wings. There are only 6 notes in the entire song and they are just the same 2 notes repeated at 3 different places in the song. Hope this helps if you are having trouble.

The songs I felt had the least amount of parts were:

INXS Need you tonight - one pattern intermittently repeated

Slipknot Before I Forget - No chords, mostly blue 2 then a couple of not unreasonable busy sections

Marilyn Manson The Beautiful People - I just found it ridiculously easy.
2 different sections throughout then changes up at the end.

guarantee you play through twice (once to learn) and you could probably 100% these

Few others that are VERY simple:

Warren Zevon - Werewolves of London - same path thru-out, little scale near end, but really doesnt matter.

B-52s - Rock Lobster - Same pattern repeated. If you've not got it by the time he says "Whale" - restart as they're are no Key notes after that.

(best to have the goal achievement playing whilst going for this - you can see the % while you play)

Another DLC song that's pretty easy on keys is "Crawling" by Linkin Park. After the opening it's mostly just a few sustained notes throughout the rest of the song and a couple repetitions of the opening pattern.

"Let Me Roll It" by Paul McCartney and Wings is also fairly easy.

Rock Band 3 on-disc:
"Need You Tonight" by INXS

Go into Practice/Train Song mode (press the Y button to get to the song details). Choose Train Song to find the correct keys to hit. You need to hit all 3 keys at the same time, every time. If you can master that, you're good to go. Training should last less than a half minute. A video can be found below.



DLC:
"Helen Wheels" by Paul McCartney & Wings

Go into Practice/Train Song mode (press the Y button to get to the song details). Choose Train Song to find the correct keys to hit. You need to hit only 2 keys, one after the other near the end of the "Helen (helen)! Hell on wheels!" part. This occurs 3 times throughout the entire song for a total of 6 notes. The first 2 notes you hit will give you overdrive. If you can master that, you're good to go. Training should last less than a half minute. A video can be found below. Too easy right?

Download links:
"Helen Wheels" by Paul McCartney & Wings (single)
OR
Celebrating Band on the Run Pack (includes "Helen Wheels" and 3 other songs by Paul McCartney & Wings)



Rock Band Network (RBN) DLC:
"Garble Arch" by Blame Ringo

Since this one is a Rock Band Network track, you'll need to make sure that you download the full song. Achievements, leaderboards, and some other features (such as practice mode and train song) are disabled with the trial/demo song. "Garble Arch" was authored by DLCquickplay.com.

Go into Practice/Train Song mode (press the Y button to get to the song details). Choose Train Song to find the correct keys to hit. There are 8 total notes in the entire song (4 different chords containing only 2 keys). I highly recommend practicing the ending of the song as there are NO NOTES for over 2 minutes into song. The only section the keyboardist plays is the ending. If you can master that, you should be good to go. This one make take a bit to learn, but not as long most other songs. A video can be found below.

Download links:
"Garble Arch" by Blame Ringo (RBN single - full song)



FYI: You can play any song with NO-FAIL MODE enabled and STILL UNLOCK THE ACHIEVEMENT. In other words, you could play "Rainbow in the Dark" by Dio and spam (i.e. randomly hit) the correct keys to unlock this achievement. And yes, I actually used this method to unlock it (before the release of "Garble Arch" noted above).



NOTES:

As mentioned before, you might want to go and play the goal itself instead of going into Quickplay to choose songs.

CAREER -> MY GOALS -> PRO KEYBOARD -> GENERAL PRO KEYBOARD GOALS -> 90% EXPERT PRO KEYS (the red 90% keyboard icon)

Simply press the green A button to play the goal. When the song plays, you'll see your percentage of notes hit in the upper right corner. It needs to be 90% or higher and will turn green when it has.


VIDEO CREDITS
The videos below are NOT mine. Credit for these videos belong to the following YouTube users (in order of appearance below).
Need You Tonight (Rock Band 3, Pro Keys Expert, Gold Star FC): mikefromsantee
Paul McCartney - Helen Wheels - Pro Keys Expert FC GS 1st Place OMG: DreadfulRay
Garble Arch - Blame Ringo Expert All Instruments RBN thenewnoelisoncruz

This is a decent list, though there are other songs that are just as easy, though mostly Tier 0-1 songs.

These include:

Tegan and Sara: The Con.
No chords for its entirety, opening with fairly easy single sustains. There are two identical sections towards the middle and end which alternate between four close keys and is not hard to nail with a little practice.

Metric: Combat Baby
Very easy single sustains around the start, followed by a mildly tricky alternating pattern that can be nailed with some practice. Chords can be daunting for new players but they are few and far between.

The Sounds: Living In America.
Notes you need to hit are quite close together and there are no chords present. There is a tricky part towards the end that will most likely get beginners but it gets easier with practice and shouldn't really inhibit the 90% requirement.

Hope this helps for people who want a bit of variety. :).