Most practice sessions are decided in the first ninety seconds, by whatever your hands reached for. This turns the minutes you have into an ordered set of blocks with a length, a purpose, and something specific to do in each one.
The problem this solves
An unplanned practice hour has a predictable shape. Ten minutes of playing what already sounds good, twenty on the thing you were working on last time until it stops being fun, then the rest on something else entirely. Nothing in that is lazy. It is what happens when the decision about where the time goes is made forty separate times, at the instrument, by someone holding a guitar.
Making the decision once, before you start, is the whole trick — and it is why the answer has to be specific about minutes. A block with no length is a suggestion. Fifteen minutes on the bar that breaks first, followed by nine on tempo, is a session. If the problem is bigger than one session and your playing has stalled generally, why guitar practice plateaus is the better place to start.
How this works
Fifteen minutes divided five ways is three minutes a block, and a three-minute block is mostly the setup: finding the passage, setting the metronome, remembering what you decided last time. The builder refuses to produce that. Blocks that fall under their minimum are removed and their minutes are given to the ones that are left, so fifteen minutes comes back as two blocks that can actually be run rather than five that cannot.
It also tells you which blocks it dropped and what each one needed, because “there was no room for the cold-start test” is useful information about your week. If most of your sessions are coming back with two blocks, the answer is not a cleverer split — it is a schedule that survives a real week.
Each focus carries its own weighting across the five blocks, and the block that repairs the thing you named is guaranteed the largest share of the session. Memorising a song puts the second largest share on playing from memory and almost nothing on tempo work; raising a tempo ceiling reverses that. At sixty minutes both produce five blocks, and the two sessions are not the same session with different headings on it.
General upkeep is the exception, and deliberately so. With nothing named as broken there is no repair target worth the largest share, so the weight moves to playing complete music under some kind of pressure. At half an hour or less the upkeep session drops the repair block entirely rather than inventing something to fix. What that block should contain when you do have a target is deliberate practice on guitar.
This tool knows how many minutes to spend on tempo work. It does not know what tempo you are on, what you are aiming at, or how big a step your hands can absorb, so it does not pretend to. The tempo ladder builder is the tool that answers those, and its rungs are what the tempo block here is for. Run the two together: this one decides the minutes, that one decides the numbers.
The rules it follows
Two players entering the same length get different sessions, because the shape is derived from the focus and from how much time there actually is.
Every block is a whole number and the blocks total the length you entered. Rounding each block's share on its own drifts by a minute in either direction depending on the total, so the leftover is handed out deliberately instead: to the blocks whose share was cut hardest by the rounding.
Each block has a size below which starting it costs more than it returns. A block that lands under that size is removed and its minutes go to the blocks still standing, so a short session comes back with two real blocks rather than five that are each too small to begin.
Whatever you chose to fix gets more time than anything else in the session, guaranteed rather than usually. A focus that changes the labels and not the shape of the session is decoration, and this one changes the shape.
At five minutes there is one block and it takes all five, because a plan with nothing in it is not a shorter plan. The block you get is the one your focus pointed at.
Wherever there is room for it, the last block puts the guitar down for two minutes and then asks for one attempt with no run-up. What you can only play while already warm has not been learned yet, it has been loaded.
There is no account and no upload. The length, the focus, and the blocks you tick off are stored in this browser only, and the clear button removes them.
What to put inside the blocks, and what to do when one of them stops producing change:
Answer a short set of questions and name the part of your practice that stopped producing change.
Turn one difficult passage into a tempo ladder with a starting speed, a target, and steps between them.
Why duration is the wrong variable, and what a 10, 25 or 60 minute session should contain.
What to do with a practice hour so it changes your playing instead of filling the time.
Building practice around a weekly total and one protected session, instead of a daily streak.
What deliberate practice means at the instrument, and how it differs from playing something again.
Check a song against the parts that break under pressure before you call it finished.
A session builder can tell you to spend fifteen minutes on the bar that breaks first. It cannot tell you that the bar breaks because your picking hand is anticipating the change. The founding room is being assembled for that part: a small crew, a weekly recording, and one correction that changes the next session.
Applying starts a fit conversation. It does not charge you or create a commitment.