perf09 drums v7, your cymbal fix plus the ride bell

v7 starts from your own v6 pass, the one that moved the cymbal work onto the ride, and puts the ride-bell accents back on top. 574 of the 591 notes are byte for byte your v6. The only change is 17 ride hits now voiced as the bell.

The two things that were wrong in v3

What v4 does instead

Your three stem MIDIs are the skeleton. Their ticks are never touched. Nothing anywhere in the part is placed from a guitar onset, and there is no tempo grid in the build at all. Measured after the fact, the 132 added notes sit a median of 223 ms from the nearest guitar onset.

Hear it

Your kit map, verified

Read from /Volumes/T7 Shield/BFD Drums/BFD3/Maps/Alesis Nitro bc3.bfd3map and cross-checked slot by slot against your Key Map screenshots. All sixteen agree, which fixes the octave question: BFD3 displays C3 as MIDI note 36. The seven rows in green were empty and are now filled.

The seven empty keys, now filled

Each value below is copied verbatim from a shipped BFD3 map, your own bc3, the built-in BFD 3.0 default, or the built-in General Midi map. No articulation index is guessed. The new map is perf09 bc3 plus bell.bfd3map, a new file that leaves your bc3 map untouched.

Only the bell is used in the part, since that is what you asked for. The other six are available on your kit the moment you load the map, an edge for a ride wash, a cross-stick for the quiet verses, a foot chick, and three chokes for cutting a crash or the ride off short.

How the bell was placed

The bell is an accent, so it goes on the loud ride hits. In the heavy ride section (bars 28 to 47, which is 48.4 to 83.2 seconds on the beat grid tracked from MIDI kick.mid, MIDI snare [2026-07-23 174311].mid and MIDI cymbals [2026-07-23 174806].mid, the same grid the form table above is built from), the ride onsets whose cymbal-lane peak sits in the top quarter, or that land on a bar's downbeat and are not soft, are voiced as bell. In v7 that is 17 bells across 53 to 77 seconds, picked from the 57 ride hits your v6 has in that window. Every bell note number is 53 in the delivered .mid, and every one sits on a ride hit that was already in your v6, so the bell never adds a note in time, it only changes the sound of a hit you already played. The remaining 49 ride hits stay on the bow.

What was added, and where it came from

How it was measured

Every audio number on this page comes from a run of build_v4.py over the perf09_v4 stems using librosa 0.11.0, soundfile and numpy, on ~/venvs/audio_midi_311/bin/python3. Onsets: librosa.stft(n_fft=1024, hop_length=256) into librosa.onset.onset_strength into librosa.util.peak_pick. Band energies and decay ratios: numpy.fft.rfft over a Hann window at the onset (attack 0 to 80 ms) and after it (sustain 300 to 900 ms). Spectral centroid for tom pitch is the first moment of the same rfft. Peak amplitude for velocity is numpy.abs(...).max() over a 50 ms window in the lane. MIDI read and written with mido at 96 ticks per beat.

Lane reality gate first, so no number rests on a hallucinated stem:

The toms lane is 24 times quieter than the snare, which is why a tom has to beat both the snare and the kick lane at the same instant before it is written. Six passed.

The cymbal split

This split is the earlier v5 read of the cymbals, kept here for the record. Your v6 pass folded the crashes and the split hats onto the ride instead, and v7 follows your v6. The bell placement above runs on v6's ride hits, not on this split.

Across your 229 cymbal onsets the v5 read was: 97 closed hat, 63 quarter-open hat, 38 open hat, 51 ride, 9 crash. The loud onsets cluster between 53 and 78 seconds with peaks five to ten times the median, and their energy sits in the 2 to 6 kHz band rather than above 8 kHz. That is a ride being hit hard through the heavy section, with crashes where the ring is long and the next hit is more than 0.65 s away.

Verification

• 574 of 591 notes are byte for byte your v6, same note number at the same tick. The onset-tick set is identical, so nothing moved in time.
• 17 of 17 bells land on a tick that was a ride in your v6. The bell only re-voices a ride hit, it adds no note.
• 0 of 591 notes land on a key outside your map. v3 had 88, which is 12% of it silent.
• All 7 empty keys filled and re-parsed: the new map reloads and reports the exact slot and artic written for each of notes 37, 41, 52, 53, 54, 55, 56. Note 53 reads slot 8 artic 1, the bell.
• Last note at tick 18016 = 93.83 s. 96 ticks per beat, flat 120 BPM, the same encoding as your guitar and bass stem MIDIs. Your session runs at 120.00, so it drops in with no stretching.
• Preview mix peaks at 0.926, no clipping.

Files

To load the map: in BFD3, Key Map tab, Tools, Load Map from file, pick perf09 bc3 plus bell. Then drag the v7 MIDI onto the track at 120 BPM.