A beat-by-beat look at one ten-second piano loop: what it does, measured from the audio, and why those choices read as nostalgia.
Follow the recording, or choose Chord Preview to compare the generated chords.
Play the instrumental to follow the recording. Choose Chord Preview to compare sus4, the Gø7 walk-down, and the muffle filter with a simple synth.
The instrumental is ready to play here. Click a brightness bar to jump to that pass. You can also hear the official upload on YouTube.
The loop spends about six seconds reaching for a resolution, gets it for a little over half a second, then slides back into minor. It repeats 37 times with almost no change. A filter keeps muffling and clearing it, and the piano itself sounds like an old record: slightly flat, dark and narrow. Each of those choices points at something you can almost get back to.
The whole instrumental is built on a single four-bar phrase. Each pass lasts 10.1 seconds, and every pass is at least 91% similar to the average one. Across six minutes the loudness moves by only 2.6 dB, so nothing builds and there is no climax.
It doesn't end on a final chord either. It fades out over the last thirty seconds. In a study in Psychology of Music, listeners tapped along to a pop song that either faded out or stopped. With the fade, many kept tapping after the music was gone. A fade suggests the song is still playing somewhere you can't hear it.
In the middle of the loop a D♭ sits on top for ten beats while the bass falls by fifths underneath it: F, B♭, E♭, A♭. The same note means something different over each chord. It is the minor 3rd of B♭m9, the 7th of E♭7sus4, then the suspended 4th of A♭maj7sus4. Over the home chord it sits one step above where it wants to be, on C.
On beat 15 it finally drops to C. That is the home chord with its major 3rd, the warm resolution, and it lasts one beat, about 0.6 seconds. Then the bass steps down to G and the loop falls back into F minor.
A note that leans on its neighbour and then resolves down by step is called an appoggiatura. The music psychologist John Sloboda found it is one of the devices most reliably linked to tears and chills. This loop does it every ten seconds. The E♭ bar does a smaller version, letting its 3rd through briefly on beat 11.
Try it in the player. With the sus4 chords off, C arrives two beats early and stays, so you land as soon as you get home and most of the ache goes. With the Gø7 off, the bass stays on A♭ and nothing pulls the loop back to minor.
Read in A♭ major, the progression is vi–ii–V–I, the backbone of mid-century jazz standards. You have heard this motion your whole life in old films, lounges and background music, which is part of why it feels familiar the first time.
The minor chords also hide major ones. Fm7 is F–A♭–C–E♭: take away the F and A♭–C–E♭ is an A♭ major chord. B♭m7 holds a D♭ major chord the same way. F minor and A♭ major share all seven notes, so the key itself sits between sad and warm. Published transcriptions disagree about which one the song is in, and the audio splits the difference: the loop spends most of its time on F minor while every chord points toward A♭.
Most of the arrangement comes from running the same loop through a filter that opens and closes. In 16 of the 34 passes before the fade, the piano's upper range drops by about 18 dB (half-muffled) or 27 dB (only the low end gets through). The song opens fully muffled and keeps going back to it. From about 4:33 to 5:13 the low end drops out instead.
Hearing the same phrase sharpen and blur again is close to how a memory comes back. That reading is interpretation. The filter moves themselves are measured.
Put together, you hear an old-sounding loop under present-day drums.
The eighth notes are straight, but the sixteenths between them land about 60 ms late, at roughly 69% of the way through each eighth. That is a little heavier than triplet swing (67%). It gives the beat a lilt that feels relaxed and never urgent.
The piano comes from Nana Caymmi's recording of Ivan Lins' Tens (Calmaria). That is Brazilian MPB, a tradition built around saudade, a Portuguese word for an aching longing for something absent. Nujabes cut a few seconds of it and replays them over and over, away from the song they came from, the way a memory replays a moment.
Part 3 first came out in 2005 on Nujabes' album Modal Soul, with Shing02 rapping about the power of music. Nujabes died in 2010, before the series was finished. Shing02 completed it, and the six parts were collected as Luv(sic) Hexalogy in 2015. Many listeners first found Nujabes through Samurai Champloo or the lofi hip-hop streams that grew out of his sound, which ties the track to a particular stretch of their own lives.
The 6:14 instrumental was analysed with the Python audio library librosa. A beat grid was fitted to the drum hits, the loop was averaged across all its passes, pitch content was split into bass and upper registers, and frequency bands were tracked pass by pass. Chord and pitch readings from mixed audio are estimates. These matched the published transcriptions.