Hi-Fi RUSH

While this achievement sounds straightforward in terms of what you have to do, getting it is not straightforward though. As the description says you need to get an S rank in every Chorus (AKA fight) for a stage (a Track), and yes, you can do this on easy too… but that still doesn’t make it easy, per se.

First things first, let's talk about the easiest chapters. There are 4 in my opinion that this is the easiest to attempt this on.

• Stage 3, as it’s boss free.
• Stage 6, as again, it’s boss free.
• Stage 9, as it’s just one boss fight.
• The same goes for Stage 12, and although he is the final boss, it’s still only one stage.

To be fair though, whichever chapter you’re comfortable with works here. Chapters 1 and 2 are easily viable options as well.

Now, let’s talk how to get an S rank, which is made up of three parts.

• Score - This is the hardest one to probably get an S rank on early on. In order to get a high score, you should do the following:
  • Combos - Keeping the combo going is vitally essential, as you’ll get points bonuses for every milestone of combos. Also, getting hit and dropping your combo gives you a 0.8 multiplier, thus meaning you get less points while the meter is still running. If you can learn Dodge Counters as well, they reward big points and also keep your combo alive. To give you a rough indication as to how important the combos are, take a look at the points below. The jump from 40 to 50 is immense. If you score over a 50 hit combo in a fight, chances are you’re getting an S rank for Score.
    • A 10 hit combo is worth 420
    • A 20 hit combo is worth 640
    • A 30 hit combo is worth 960
    • A 40 hit combo is worth 1,280
    • A 50 hit combo is worth 2,240
  • Variety - This is perhaps the most important one, because if you use the same move over and over, the game will penalise you for that. If you do it twice in a row, you’re getting a 0.8 multiplier penalty. If you bounce from a few combo sets to another though, you’ll be okay. 
  • Multipliers - There are two really helpful multipliers that you should be looking out for: the Magnet Link, where you use the magnet and then go straight into a combo (that gives you a 1.2 multiplier); and more importantly, the Aerial Rave (which gives you a 1.5 multiplier). Learning how to get someone into the air ( break  is great, as is the and then ) can take you from an A rank to an S rank.
  • Partners - Calling in your partners, and mixing them up, will give you bonus points. This should be in your arsenal to use every 5 seconds or so. Spamming all three after one another is also great, as you’ll get a mix up bonus too. Speaking of partners and multipliers, if you perform a Jam Combo ( break and then ), you’ll get a whopping 2x multiplier (you'll need Reverb for this though). So, don’t sleep on your partners if you want an S rank. If you can combine that with an Overkill on an enemy too, you’re looking at points galore.
• Just Timing - This is all about movement. Everything you do in a fight should be on the beat. If you dodge, do it to the music. If you jump, do it to the music. If you attack, do it to the beat. While the Score category can be manipulated somewhat, this one is all about playing to the rhythm. Don’t forget to use the world, the UI and its pulsing, as well as the Rhythm Assist (the view button) to help you find the rhythm and stick to it.
• Clear Time - The quicker you beat the stage, the higher the score and the bonus. The trick to this one is just be relentless and multi-task. That's it.

Generally, getting 2 S ranks and an A rank at the end of a Chorus will give you an S rank overall. That’s what I found anyway.

And finally, in terms of what chips you use:

• Rhythm Meter Rush is especially good if you’re not used to holding down a combo. If you are, then this might be redundant.
• Combo Holder is good as well, and gives you a bit longer to keep that combo alive.
• Parry Charge is great if you want to build your Reverb Gauge, which you can then use on Special Attacks and Jam Combos.