Noticed that there wasn't 5 star cutoffs listed anywhere and would be helpful for whichever songs you are struggling with. These are only approximate and not exact but these scores are really close to 5* on Hard difficulty
Before tackling this, I suggest you make sure you're holding the deck the right way, make sure it is your thumb on the outside of the turntable and not your pinky, this will ensure better control over the turning of the turntable. In other words, buttons right means use left hand and buttons left means use right hand. If you're thinking of moving onto expert then this is important.
The game will not penalise you for moving the turntable provided you are not pressing any buttons that you shouldn't be at the time so don't think you have to keep it perfectly still all the time.
Concerning the Effects dial, I learned that it is better to use one finger to turn the dial rather than use 2 fingers because using one finger allows the rest of your fingers to be nearer the crossfader and it means less risk to missing crossfades.
With Rewinds, you get a rewind at every 50 note streak, however you can only have one rewind and until you use this rewind, the game won't even start counting towards another rewind until this rewind is used up (back at where you originally used it).
For example: If you use rewind at 59 note streak and once the rewind is used up (back at where you originally used it), assuming you haven't messed up during the rewind or after then you will get your next rewind at 109 note streak.
When making rewinds, try and make sure you do a 360 revolution and then stop the turntable near the buttons, don't make it spin multiple times otherwise you are almost certain to miss the notes. Also make sure you don't accidently hit the buttons during a rewind, this could be the difference between a x8 and a x2 multiplier!
And for crossfade spikes, I found that you do not have to return the crossfade all the way back to the middle but you only have to bring it halfway back towards the middle and the game will count it as returning to the middle. This helps out a lot with sections where there are many spikes in a row that are on the same side, but doesn't help with the alternating spikes sadly, that really requires good timing and listening to the track.
Keep in mind that for the Guitar and DJ tracks (at the bottom), you cannot use rewinds so these will be harder to 5 star and require more effort.
Some notes for especially hard tracks:
Groundhog: You must be able to get 2-3 rewinds off in the first 2 sections to have a chance at this. In the 3rd and 4th sections, the easiest sections to combo are where the crossfades are going from left to right and back to left constantly and there is a constant pace of red taps. There are 2 sections like this and you can easily earn rewinds on these with practice. Although it is easy points between song sections (where the track is mocking you) try and resist using Euphoria or Rewinds because the points earned here are minuscule.
Rockit: I found this much harder than Groundhog, this song really makes you work for a 5 star. I saved Euphoria for when the crazy left and right crossfading with spikes sections came along, making sure I hit the single directional scratches to keep 8x.
However, I saved the rewinds for the areas of constant green scratches, these are near the beginning and there is an extended section about halfway through. I would personally avoid using rewinds during the crossfades unless you can handle it without messing up.
This song pretty much goes Scratching section, Crossfading section, Scratching section, Crossfading section.
I Heard it through the Grapevine/Let's Dance: The only things that make this song hard is the Euphoria in choke zones and the difficulty of getting rewinds. There are a lot of fast crossfade spikes on this song and if you have Euphoria then save them for these because getting rewinds on this song will help a lot. This song is only about 2-3 minutes long so if you get off to a bad start, you are better off starting over.
Monkey Wrench/Sabotage: The hardest of the guitar tracks in my opinion, but only because the song seems out of sync on the green stream, you have to hit the green stream scratches and taps slightly earlier than it says. Blue crossfades seem out of sync also. I always make sure the Euphoria at the very start is hit because there are crossfade spikes about 30-40 secs in followed by crossfades, I use the Euphoria just as the spikes start and it lasts until the end of the crossfades and you don't have to move it at all. This should get you to 45,000 pts assuming you haven't messed up to this point.
There are more crossfade spike sections later in the song but concentrate on getting the Euphoria for now, even if you mess up a few times you can still get the Euphoria and 5 star this song, it's all about where you use the Euphoria.
If rewinds were allowed, this song would not be as hard as it was to 5 star.
Beats and Pieces: Not exactly difficult on hard but can catch you out if you're not used to 5 minutes of constant scratching. There are 8 sections to this song and each section gets progressively harder, so if this one is a struggle then focus on the first 4 sections because if you master those then you have 5 starred the song before the last 4 sections.
There aren't many crossfades in this song so this one will require effort to 5 star. This song gets even worse on expert so count yourselves lucky, it jumps to being the hardest song in the game (next to Rockit).
Satisfaction/Elements of Life: This song has a high 5 star cutoff and is mostly a tapping song and will test your switching between the buttons on the deck. If you can do the taps then most likely you will get this in a few tries. The good news is taps are worth a ton of points under 8x multiplier.
Daft Punk Megamix 1 and 2: Daft Punk tracks are difficult in this game, these songs both have high 5 star cutoffs and they are multiple Daft Punk tracks strung together. Not much advice I can give on these other than use what you have learned and keep that streak.5 Star CutoffsIntensity:Very Low
Ain't no Love in the Heart of the City/Fuzz and them 49,000
Another one bites the dust/Da Funk 78,000
Born to Roll/Mr. Big Stuff 79,000Intensity:Low
Zulu Nation Throwdown/Get Down 119,000
Ice Ice Baby/U Can't Touch This 133,000
I want you back/Semi-charmed Life 136,000
Jayou/Big Beat 134,000
Insane in the Brain/Spooky 87,000
I heard it through the Grapevine/Feel Good Inc. 156,000
Izzo (H.O.V.A)/I want you back 158,000
Bustin' Loose/Bust a Move 175,000
We Will Rock You/Robot Rock 142,000
Feel Good Inc./Atomic 110,000
Boom Boom Pow/Satisfaction 176,000
Disturbia/Disco Inferno 152,000
Insane in the Brain/The Edge 141,000
Poison (Bell Biv Devoe) 109,000
Shout/Six Days (Remix ft. Mos Def) 152,000
Poison/Word Up! 127,000
Fix Up, Look Sharp/Organ Donor (Extended Overhaul) 104,000
Bustin' Loose/Time of the Season 97,000
Hollaback Girl/Give it to Me 152,000
Hollaback Girl/Feel Good Inc. 172,000
Ice Ice Baby/Straight Up 160,000
Shut 'Em Down/Where It's At 139,000
Put Your Hands Up for Detroit/I Can't Stop (DP Remix) 146,000
Here Comes My DJ/Cars 142,000
Izzo (H.O.V.A)/My Name Is 204,000
Day 'n' Nite/Boom Boom Pow 165,000
Da Funk/Strange Enough ft. Karen O, ODB & Fatlip 137,000
Disco Inferno/Last Night a DJ saved my Life 184,000
Bittersweet Symphony/Rock the Bells 178,000
Shout/Eric B. is President 132,000
Another One Bites the Dust/Brass Monkey 144,000
Disco Inferno/Let's Dance 187,000
Just to get A Rep/Shook Ones,pt.2 157,000
Bring the Noise 20XX/Genesis 141,000
Ain't no Love in the Heart of the City/How Do You Want it 117,000
My Name Is/Loser 173,000
Six Days (Remix ft. Mos Def)/Where it's at 134,000
The Edge/Eric B. is President 113,000
Megamix 2 (Daft Punk) 285,000
Beats/Big Beat 214,000
Change Clothes/All Eyez on me 152,000
Around the World/Bust a Move 182,000
Jack of Spades/Short Circuit 192,000
I Heard it through the Grapevine/Let's Dance 120,000
All Eyez on me/Bittersweet Symphony 189,000
Excuse Me Miss/Give it to me 177,000
Megamix 1 (Daft Punk) 207,000
Good Thang/Big Beat 201,000
Last Night a DJ saved my Life/Word Up! 197,000
Jack of Spades/Let's Dance 123,000
Lookin' at me/Hey Mama 164,000
Paper Planes/Lookin' at me 212,000
I Want you back/Just to get a rep 115,000
How Ya Like me now/I Like to move it 186,000
Somebody Told Me/Pjanoo 139,000
Hollaback Girl/Last Night a DJ saved my life 193,000
Hella Good/Television Rules the Nation 165,000
Tutti Frutti/Beats 136,000Intensity:Very High
Paper Planes/Eric B. is President 231,000
Robot Rock/Al-Naafiysh (The Soul) 242,000
Jukebox Hero/DJ Hero 130,000
Here's a little something for ya/The Number Song (2009) 144,000
Nothing but you/I Can't Stop (DP remix) 276,000
Six Days (remix ft. Mos Def)/Annie's Horn 196,000
Rockit (Herbie Hancock) 329,000
Strange Enough ft. Karen O, ODB & Fatlip/Theme from Shaft 167,000
Beats and Pieces (Scratch Perverts) 228,000
Satisfaction/Elements of Life 346,000
Universal Mind Control (UMC)/Jeep A** Gutter (Remix) 233,000
Groundhog (Noisia) 442,000
Lee Majors Come Again/Da Funk 149,000Guitar and DJ songs
Beverly Hills/Fresh Rhymes and Videotape 113,000
Big Beat/Lapdance 140,000
Jukebox Hero/DJ Hero 131,000
I Want You Back/Semi-charmed Life 152,000
Disturbia/Somebody Told Me 144,000
Ace of Spades/Groundhog 146,000
Monkey Wrench/Sabotage 133,000
Play that Funky Music/Just to get a rep 238,000
Bring the Noise 20XX 174,000
Fight! Smash! Win!/Intergalactic 105,000
If there is any way I could improve this solution then please leave a comment