The missing manual.

It's guitar's most important skill.

From simple strums to flashy solos, everything you play depends on rhythm.

And yet, we neglect it.

From books to YouTube to music school, rhythm is treated as an afterthought… when it’s mentioned at all.

And so we struggle. We plateau. We get stuck.

But we don’t have to.


GuitarOS courses have helped over 3,000 students get unstuck with the instrument.

👉 between Gumroad & CourseScore, GuitarOS courses have a 100% 5-star rating.
👉 RhythmOS offers a no-questions-asked 30-day money-back guarantee… but fewer than 1% of people ask for a refund

What students are saying:


"Achievable modules. Clear, actionable elements. No fluff. Just small, everyday victories that compound." - Mario, California


"This emphasis on learning to play real songs gives me the context to know exactly where the gaps are in my playing." - Mike, Atlanta


"Great courses for weekend warrior musicians like me. The use of popular music to teach concepts is a lot more fun." - Kalimar, Grade 43 Podcast

Unlock RhythmOS Today


What's Inside?

Unit One

  • You'll learn to think like a rhythm section player...
  • ...and understand the most fundamental rhythms...
  • ...that are in every style of music...
  • ...and we'll do that by looking at real songs.

(Like these two examples below...)

Unit Two

  • In this unit, we'll move on to the next logical set of rhythms.
  • We'll learn them in the Western style...
  • ...but also we'll bypass the logical part of the our brain with "rhythmic solfège."
  • We'll also look at funk rhythms...
  • ...and briefly look at the basic techniques needed to play them.

Unit Three

  • We'll break out that "rhythmic solfège" again...
  • make sense of something that traditional (Western) methods suck at...
  • ...and we'll play one of the most joyful sounds in all of music: the shuffle.
  • No surprise here: we'll do this be learning REAL songs.

Unit Four

  • The first three units will equip you for 90+% of musical situations.
  • This fourth unit will prepare you for the rest.
  • Will we cover the entirety of music? No, of course not.
  • But in true teach-a-man-to-fish style, we'll give you the tools you need to make sense of anything we didn't specifically cover here.
  • (And again, we're not gonna do this with theoretical examples—we'll use REAL songs.)



Seeing concepts applied to numerous real-world examples is invaluable.




More kind words from students

Frequently Asked Questions

Who is this course for?

Any musician who wants a no-BS explanation of the most important concept in music, explained with examples from real songs.

Is rhythm really that important?

The right note at the wrong time is still wrong. A "wrong" note played in time usually still sounds pretty great.

Getting your time & feel together is the #1 thing you can do to be a better musician.

The ideas in RhythmOS are 50% of that equation—naming & understanding the things you hear (because how are you supposed to improve a system you don't understand?).

Why should I listen to you? Who are you?

My name is Josh Skaja.

By pure dumb luck, I went from "guy who plays with amateurs in half-empty bars" to "guy who plays with badass pros in sold-out two-thousand seat venues."

As you might imagine, this was both an amazing opportunity AND a terrifying trial-by-fire learning experience.

You absolutely do not have to listen to me, but I have seen what the badass pros are focused on, translated those ideas for normal people like us, and turned them into these courses. Your call.

What will I learn in this course?

Music is made up of:

  • pitch,
  • melody,
  • harmony,
  • rhythm,
  • timbre,
  • & intensity.

Of these, rhythm is the most important—and the most often overlooked.

In RhythmOS, you'll learn how to think about rhythm in a way that's simple & clear... but NOT dumbed-down.

Armed with this knowledge, you can make anything sound good, no matter how simple or complex.

Ok, got it. This must be expensive, right?

Nope. It's $50.

Ok, but still... is it worth it?

I spent a decade struggling with this.

I've wrestled with these ideas until they made clear, intuitive sense.

You can skip all the confusion & frustration and go straight to unlocking the most important concept in all of music.

How long until I see results?

Well, the course takes about two hours to go through.

  • If you buy and don't take it, expect to get nothing from it.
  • If you just read the descriptions & listen to the examples, your brain will be primed to understand the most important part of music.
  • If you actually do the things I suggest (which doesn't really take any extra time), you'll be halfway to being a badass. (The other half involves recording yourself, which is a whole other course.)

Does the course come with email or phone support?

No, it's designed to be self-guided and self-paced.

Do I get lifetime access?

Yes! You can access it for as long as you'd like with no extra payment.

Ok. What do I do next if I want to enroll?

Click the "Unlock Lifetime Access for $50" button below.