Raw waveform demos (no envelope), open up bass lowpass to 1200

Basic waveforms now play without envelope shaping so you hear
the raw timbre. Complete Example bass at 1200 instead of 600.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/generate_audio.py

@@ -393,7 +393,7 @@ def gen_jazz_ballad():
 
 # ── Synth waveform demos ──────────────────────────────────────────────────
 
-def _synth_demo(name, synth, envelope="pluck", **kwargs):
+def _synth_demo(name, synth, envelope="none", **kwargs):
     """Short C major melody on a given synth."""
     score = Score("4/4", bpm=100)
     p = score.part("demo", synth=synth, envelope=envelope, volume=0.5,
@@ -694,7 +694,7 @@ def gen_complete_rock():
     lead = score.part("lead", synth="saw", envelope="pluck", volume=0.4,
                       delay=0.2, delay_time=0.33, reverb=0.2, lowpass=3000)
     bass = score.part("bass", synth="triangle", envelope="pluck", volume=0.45,
-                      lowpass=600)
+                      lowpass=1200)
     for chord in Key("G", "major").progression("I", "V", "vi", "IV") * 2:
         piano.add(chord, Duration.WHOLE)
     lead.add("D5", 1).add("B4", 0.5).add("D5", 0.5)

docs/guide/sequencing.rst

@@ -396,7 +396,7 @@ lead, and filtered bass:
 
    # Filtered bass
    bass = score.part("bass", synth="triangle", envelope="pluck",
-                     volume=0.45, lowpass=600)
+                     volume=0.45, lowpass=1200)
 
    for chord in Key("G", "major").progression("I", "V", "vi", "IV") * 2:
        piano.add(chord, Duration.WHOLE)