A class connection always starts with the teacher — you get a link or a code, never the other way round. Connecting is voluntary: without a class, you practise exactly the same exercises. A class and a family don't rule each other out — your device can be connected to your class and your family at the same time.
Accepting the invitation — by link or code
A tap on your teacher's link opens the class directly. Without a link, you enter the code instead on /profil in the "Join a class" card — "Did your teacher give you a code or link? Enter it here."
Confirming your name
Klavissimo shows who's inviting you and to which class, and suggests your existing profile name (editable). Right underneath, before anything happens, sits the data boundary: "Your teacher will then see how often you practise and where it sticks — never your sheet music, never recordings."
Parental consent — the actual gate
Only after that comes a page marked "FOR PARENTS": it shows exactly the one line your teacher will see from then on — name, level (or "Not placed yet"), a week of ♩ — and requires a checkbox as an explicit confirmation of being the child's parent/legal guardian (or an adult yourself). Tapping "Allow connection" is the ONLY path in the code that ever sends anything to the server; "Play without connecting" sends nothing and leaves everything as it was.
Ms Berg would like to see Mila's practice progress.
You see: practice days · scores & levels · sticking points
Never: sheet music & own pieces · recordings · email addresses
Before connecting, a page marked “FOR PARENTS” shows exactly the two lines — what the teacher will see from then on, and what never.
What arrives once you're connected
Your device shares a daily summary at most once an hour: whether you practised that day, your best scores, and up to three sticking points — only as an axis and a bar number. If your teacher sets a "practice spot" for you, it shows up in your daily plan on the next sync, marked "from {teacher}".
For parents
The consent page isn't a formality tick-box, it's a technical gate: without tapping "Allow connection", nothing is sent. Declining doesn't mean "less app" — your child practises exactly the same exercises, connected or not.
Disconnecting — any time, from either side
On /profil, a card reads "Class … · … — connected since … · shares statistics only" with "What's shared? ›" and "Disconnect". Disconnecting takes effect immediately on both sides; existing statistics disappear from the teacher's class view. If the teacher already removed the connection on her side, your device simply reports it as "already disconnected" on the next attempt, instead of showing an error. If you're already connected to one class and join a SECOND, Klavissimo doesn't silently overwrite the old one: it asks honestly first — the old connection ends only when you confirm "Switch" (and if that can't be done offline right now, the switch is cancelled without breaking anything).
Linking an email — optional, never required
Right after joining, Klavissimo offers to voluntarily link an email address — "Just in case the device ever gets lost — the email brings your class connection back. Your teacher never sees it." Without an email, the class connection keeps working exactly the same.