Built for choir singers
A choir rehearsal is a group problem being solved in public. The part you cannot hold, the vowel that sticks out, the entrance you guess at: none of those get fixed in the room, because the room is busy. They get fixed in the twenty minutes nobody watches.
This is not a memory problem and it is not a confidence problem. Singing a line while a different line moves against it is a distinct trainable skill, and almost nobody trains it in isolation, because you need a second part to practise against and a choir is not available on a Tuesday night.
Learning a part by playing it back is learning to follow, not learning to lead. The test is whether you can produce the line cold, and most singers discover in rehearsal that they cannot.
Almost always a vowel problem rather than a volume problem. One singer's bright "ah" against four dark ones is audible from the back of a hall no matter how quietly it is sung.
The full curriculum is still there. These are the areas weighted up for you.
Singing a third or a fifth while a melody moves against it, and staying on your line when the voice beside you is louder. The largest single block of the curriculum.
Interval recognition and singback, so a written line becomes a sound you can hear before you produce it rather than a shape you approximate.
The difference between a section that sounds like one instrument and a section that sounds like six people. Trained directly rather than corrected by a conductor.
Sitting under the section in one passage and carrying it in the next, deliberately, rather than at whatever volume feels natural.
What this does: gives you a different 15 to 20 minute session each day aimed at holding a part, hearing an interval, and matching a vowel, and measures your pitch and timing so you can see whether it is working. What it does not do: replace your director, who hears the whole section balance, or replace a voice teacher, who hears your tension and your larynx. It also cannot rehearse your specific repertoire with you. This is the mechanism between rehearsals, not the rehearsal.
The curriculum runs 407 exercises across 15 skill categories, and the harmony block is the largest one. Part-independence work plays a moving line against you so you are practising the actual difficulty rather than practising your own part alone and hoping.
Exercises unlock in order, so you get the next thing your ear is ready for. That matters for choir singers specifically, because the usual failure is jumping straight to four-part work when the underlying interval is not yet solid, and then concluding you are bad at harmony.
No, and it is worth naming what reading actually is here. Sight singing is interval recognition plus a sense of key, both of which are trained directly in the ear block. The notation is the easy half. Most people who say they read badly actually hear badly, and that is the fixable part.
Each singer needs their own account, since the plan adapts to the individual voice and ear. There is a free tier with one session a day, which is enough for a volunteer chorister to train seriously. What it will not do is coordinate the section for you.
The curriculum starts at lip trills and humming and gates everything behind what you have actually done, so it works at any age. It assumes nothing about your background and nothing about your repertoire.
It reports pitch matching and stability from the notes the microphone hears. Range is a separate test; neither result is a diagnosis. No signup, no card.