Weeks 3-4 · ear · two-degree solfège with established tonic
Echo Sol to Mi. The first interval every child sings.
The rule
pass: PAT-A on 8 of 10 (each note ≤ 45¢, contour exact)
Two pitch lanes — Sol on top, Mi on bottom. Each trial drops one dot in each lane; the emerald band is ±45¢ from target. Land both dots inside on 8 of 10 trials and the contour direction (Sol↘Mi or Mi↗Sol) must be right — flipping the order is the most common failure mode here.
Hear it first
Two references. The descending Sol-Mi is the “nyah-nyah” taunt — that shape is hard-wired in every culture. The ascending Mi-Sol is the same gap walked the other way. Hear the gap before you try to sing it.
What’s happening. A minor third (Sol to Mi, three semitones apart) is the universal child-chant interval — documented across every musical culture studied. Your auditory cortex already maps it from infancy; this drill ties that recognition to motor output. We anchor each trial with a 1-3-5-1 tonic arpeggio so the third you sing is a relative pitch, not an absolute Hz target. Untrained singers wobble 60–100¢ on the second note; the goal is to settle inside ±45¢ on both.
Why two notes, not just one. Single-note matching tests the audio-motor loop on one tone. The two-note pattern tests relative tuning — can you reproduce the interval, not just chase the pitch? The 2.0-second hold on each note inside ±45¢ rules out a lucky brushstroke; you have to commit. PAT-A also checks contour direction — if Sol↘Mi comes out as Mi↗Sol, the trial fails even if the pitches were close, because the relational hearing wasn’t there.
Why this is the foundation.Every ear-family lesson downstream — so-mi-la (add one syllable), three-note patterns, third-echo, the diatonic scale — assumes you can lock a minor third between two labeled degrees. If Sol and Mi aren’t solid here, the four-note patterns and full solfège ladder won’t settle. This is the smallest possible solfège step.
Session ahead
10 prompts · tonic arpeggio cue then two-note Sol/Mi pattern · hold each note inside ±45¢ for 2.0s · 8/10 with contour exact promotes.