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 Expert 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 60 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 69 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 129 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.
Song specific advice
Rockit (455,000 for 5*) - This song doesn't differ much to hard difficulty, the only noticeable difference is the scratching sections will now be trickier and require more attention. Despite this though, I think the scratching sections are the best places to get your points from your rewinds.
This song starts with a small scratching section, it is possible to get a rewind off of this if you full combo it (before the 80s sound kicks in), if you can do this then it will help enormously towards the 5* because most of this is alternating scratches, there is a triple up scratch in it somewhere in the middle though (it's easy to spot).
During the 80s sound, there is a Euphoria phrase just before the first crazy crossfading section. You should aim to get this, and activate it immediately without messing up your multiplier. This should get you x8 through a good portion of the section provided you don't miss the scratches. If you get a rewind, then it's upto you if you use it here, but I usually save it for the scratches up ahead.
There is a Euphoria before the end of this section but I've virtually never hit it because it has alternating spikes, if you can hit this then it's a bonus.
Now there will be a longer scratching section coming up, you may have a rewind here, use it after a the 3rd long green scratch plinth, just before the shorter 4 scratch plinths. You may get another rewind later on in this section, I advise you to use it as soon as possible and ideally before the repeated single scratches comes along (which I can never hit).
Now crazy crossfading section 2 will come along and this bit may make or break your 5*, it all depends on whether you have Euphoria or not. There is one last Euphoria in this section and I usually have to rely on getting it to 5* this song. If you can't get this one then I'd advise picking up another of the Euphoria phrases in the song because this section is harder than the first crazy crossfading section and you will need Euphoria if you suck at this song.
Now if you are close to 455,000 near the end, I once 5*'d this song by collecting a rewind off the final scratch sequence of this song. It's short but if you already have 40-50 note streak before it, you can get a rewind and use it just before the end to pick up extra points.
To summarize, you want to use your Euphoria as much as possible on the crossfading sections. You want to save your rewinds for the scratching sections.
Groundhog (465,000 for 5*) - This one is mostly down to how well you do the first 2 sections of the song (up until the song says "Let's call it feedback"). The first section is very easy, you should aim for 2 rewinds off of this section.
I usually save Euphoria for the second section of the song, because it will go through the 2nd Euphoria of the song which is hard to get without Euphoria, if you use Euphoria then you only have to worry about the fast scratch. Again, try and get at least one rewind here, it is harder to go for 2 rewinds here but if you can get 2 then that is a huge bonus.
Now we get to the trickier part of the mix, the 3rd section (after Feedback is mentioned). I cannot for the life of me do the crossfades/red taps with the single directional scratches, so don't worry too much if you cannot do this bit.
Later on in the 3rd section, there will be a few bits where the crossfades continue but you will have only red taps instead (with the occasional scratch or two). This is a good place to get a rewind or maybe even 2 rewinds, I found these parts to be crucial to obtaining my 5*. The last part of the 3rd section where the crossfades are quick left right motions, I couldn't combo this bit either.
By the time "I think we're coming to the end" is said, you should have the majority of your points and should have over 400,000 at least, if you don't then you may as well restart because the 4th section is the toughest and I cannot personally combo any of it, it will get you some points but it won't get you much.
One last note, don't use Euphoria or Rewinds between the sections where the track is mocking you, the points you'll get there is minuscule and you'll be much better using it where there are more actions (even if you cannot do it so well).
So to summarize, the first 2 sections try for 3-4 rewinds, use Euphoria to help you collect the 2nd Euphoria phrase in the 2nd section.
3rd section, try for rewinds on the crossfades with red taps (where there aren't scratches).
4th section, flailfest! Try to score as much as you can, any rewinds or even the Euphoria on the fast red taps is a bonus.
Beats and Pieces (388,000 for 5*) - Wow, this song is truely good at pissing me off. It is hard to keep trying at this song over and over, and the amount of times it would drop combo during the first 2 sections no matter how accurate I was, it was unbelievable. Anyway I did it and I can pass some things I learned.
To rack up the mix for you, it has 8 sections and each one is faster than the previous. They do share a common denominator though and that is the first part of each section (although the section commencing scratching pattern does change in sections 6, 7 and 8). You will need to practice this part, yes it has the hated triple up scratch but it is much easier to learn this part of the mix than try to learn other parts.
When I 5*, I got 431,000 and yes this is way over but my previous was 377,000. If you feel like you are on a good run, then when the breaks come between the sections, just pause the game, go off and walk around for 5 mins and or so to give your arms time to recover, it gives you a chance to calm down, reflect and plan out what to do next. This works wonders if you're always nervous and twitchy like me when you're doing well.
Obviously it is much easier to get the points in the earlier sections of the mix. Crimson Ridley's solution offers very good advice on this mix already, I followed his guide for the first 2 rewinds, they are perfectly placed. Aim for 2 rewinds on the 1st section.
When I got 5 stars, I full combo'd this section and I had 130,000 when I finished, I don't use Euphoria yet though.
I use the Euphoria at the beginning of the 2nd section, you need to be able to do this section pretty well also so practice this section and learn the scratching inside out. You will probably still miss despite this since the scratches are pretty fast here. If you do get the Euphoria here then don't fall into the trap of using it where the effects dial can be used which is shortly after (as the multiplier doesn't stack), using it after this is where I used it. I didn't full combo this section but I finished it with 230,000 points on my 5* run. Try to get a rewind off in the 2nd section, if not then the beginning of the 3rd section will be your next and possible last shot.
At the beginning of the 3rd section, this is possibly the last part of the mix which is decent enough for me to combo personally, try for a last ditch rewind before the mix gets much tougher. Be sure to pick up the Euphoria here aswell, I use this one immediately as it's still easier to pick up points here.
I finished the 3rd section with 294,000 points on my 5* run.
Now if you are picking up about 300,000 in the first 3 sections like I am with about 5 sections left to come, this is an excellent position to be in. Of course it doesn't mean you're home free, you should still try your hardest on each section and take breaks between the sections to be sure of maximizing your chances.
Anyway as a guide, my run finished as follows
Section 4 finished with 333,000
Section 5 finished with 362,000
Section 6 finished with 384,000
Section 7 and 8 finished with 431,000
I collected 6/7 Euphorias, I always miss the one in Section 6 where it is has a red tap in simultaneously with it near the end of a long blue scratch plinth. The others are obtainable but it's down to whether you can pick them all up in a single run. In sections 4-8, I just used Euphoria immediately to help my score as I am not consistently good at any single part of it.
I only got 4 rewinds, 2 in Section 1, 1 in Section 2 and 1 in Section 3 (at the beginning).
I hit 89% and my highest note streak was 230 which was from the beginning up until halfway into Section 2.
I wish you best of luck in 5*ing this mix, it is truely the toughest in both DJ hero games in my opinion.
5 Star Cutoffs
Ain't no Love in the Heart of the City/Fuzz and them 54,000
Another one bites the dust/Da Funk 94,000
Born to Roll/Mr. Big Stuff 97,000
Zulu Nation Throwdown/Get Down 158,000
Ice Ice Baby/U Can't Touch This 149,000
I want you back/Semi-charmed Life (DJ only mix) 153,000
Jayou/Big Beat 156,000
Insane in the Brain/Spooky 112,000
I heard it through the Grapevine/Feel Good Inc. 205,000
Izzo (H.O.V.A)/I want you back 206,000
Bustin' Loose/Bust a Move 228,000
We Will Rock You/Robot Rock 168,000
Feel Good Inc./Atomic 160,000
Boom Boom Pow/Satisfaction 220,000
Disturbia/Disco Inferno 173,000
Insane in the Brain/The Edge 183,000
Poison (Bell Biv Devoe) 127,000
Shout/Six Days (Remix ft. Mos Def) 206,000
Poison/Word Up! 158,000
Fix Up, Look Sharp/Organ Donor (Extended Overhaul) 183,000
Bustin' Loose/Time of the Season 175,000
Hollaback Girl/Give it to Me 189,000
Hollaback Girl/Feel Good Inc. 183,000
Ice Ice Baby/Straight Up 175,000
Shut 'Em Down/Where It's At 203,000
Put Your Hands Up for Detroit/I Can't Stop (DP Remix) 180,000
Here Comes My DJ/Cars 182,000
Izzo (H.O.V.A)/My Name Is 245,000
Day 'n' Nite/Boom Boom Pow 236,000
Da Funk/Strange Enough ft. Karen O, ODB & Fatlip 211,000
Disco Inferno/Last Night a DJ saved my Life 209,000
Bittersweet Symphony/Rock the Bells 270,000
Shout/Eric B. is President 195,000
Another One Bites the Dust/Brass Monkey 187,000
Disco Inferno/Let's Dance 209,000
Just to get A Rep/Shook Ones,pt.2 206,000
Bring the Noise 20XX/Genesis 223,000
Ain't no Love in the Heart of the City/How Do You Want it 166,000
My Name Is/Loser 260,000
Six Days (Remix ft. Mos Def)/Where it's at 169,000
The Edge/Eric B. is President 139,000
Megamix 2 (Daft Punk) 328,000
Beats/Big Beat 254,000
Change Clothes/All Eyez on me 210,000
Around the World/Bust a Move 235,000
Jack of Spades/Short Circuit 262,000
I Heard it through the Grapevine/Let's Dance 149,000
All Eyez on me/Bittersweet Symphony 281,000
Excuse Me Miss/Give it to me 259,000
Megamix 1 (Daft Punk) 267,000
Good Thang/Big Beat 267,000
Last Night a DJ saved my Life/Word Up! 211,000
Jack of Spades/Let's Dance 187,000
Lookin' at me/Hey Mama 189,000
Paper Planes/Lookin' at me 239,000
I Want you back/Just to get a rep 187,000
How Ya Like me now/I Like to move it 236,000
Somebody Told Me/Pjanoo 180,000
Hollaback Girl/Last Night a DJ saved my life 265,000
Hella Good/Television Rules the Nation 202,000
Tutti Frutti/Beats 202,000
Paper Planes/Eric B. is President 277,000
Robot Rock/Al-Naafiysh (The Soul) 283,000
Jukebox Hero/DJ Hero 232,000
Here's a little something for ya/The Number Song (2009) 237,000
Nothing but you/I Can't Stop (DP remix) 323,000
Six Days (remix ft. Mos Def)/Annie's Horn 266,000
Rockit (Herbie Hancock) 455,000 (3* is 227,000, 4* is 341,000)
Strange Enough ft. Karen O, ODB & Fatlip/Theme from Shaft 205,000
Beats and Pieces (Scratch Perverts) 388,000 (3* is 216,000, 4* is 294,000)
Satisfaction/Elements of Life 380,000
Universal Mind Control (UMC)/Jeep A** Gutter (Remix) 271,000
Groundhog (Noisia) 465,000 (3* is 233,000, 4* is 349,000)
Lee Majors Come Again/Da Funk 250,000
Guitar and DJ songs
Beverly Hills/Fresh Rhymes and Videotape 141,000
Big Beat/Lapdance 184,000
Jukebox Hero/DJ Hero 232,000
I Want You Back/Semi-charmed Life 216,000
Disturbia/Somebody Told Me 205,000
Ace of Spades/Groundhog 213,000
Monkey Wrench/Sabotage 188,000
Play that Funky Music/Just to get a rep 297,000
Bring the Noise 20XX 242,000
Fight! Smash! Win!/Intergalactic 157,000
If there are any mistakes in this solution or if there is any way I could improve it, please leave a comment.