Am Wed, 25 Feb 2026 08:25:17 -0500 schrieb Dan Eble <[email protected]>:
> On 2026-02-24 22:36, metachromatic wrote: > > "We don't require this level of detail in music expressions for > > dynamic ramps." > > > > You don't -- many other composers do. > > I want to correct some misinformation in Metachromatic's message for > the sake of bystanders who might otherwise be thrown off track. > > Arnold proposed this scenario: > > you specify the total duration (e.g. 4 measures), > the frequency (e.g. each quarter an update) > and the relative final tempo (e.g. 2/3) > > This describes a ramp in tempo. LilyPond MIDI output already > supports ramps in dynamics (i.e., decrescendo and crescendo) without > users having to do the math and insert absolute levels periodically > in the music expression. At the moment, I don't see anything that > would stand in the way of doing something similar for tempo changes. > To a person interested in trying that, I'd also encourage thinking > about slowing the MIDI tempo by a parameterized amount for a > parameterized time at \caesura. > > > > inability to specify tempo changes as real numbers (from tempo > > 73.241 to tempo 74.856, for example) > > Rational numbers are sufficient for these examples, and LilyPond > supports rational numbers. > > https://lilypond.org/doc/v2.25/Documentation/notation/displaying-rhythms#metronome-marks > > The MIDI output uses an approximation constrained by the MIDI design. > > The default metronome mark rounds to an integer, which is reasonable > for music of the era that LilyPond's defaults usually target. As for > many other things, the user can override the stencil or add text to > describe a tempo change in any way that can be put into writing. Hello Dan, with the relative tempo changes I'm working on I see only the usecase to show at which speed you ended up after you've executed several relative tempo changes in sequence, and there report the fractional part, too. Moreover, this usecase is limited to the 'working score', in the score one is going to publish I expect this will be removed (e.g. by tag). And yes, I've seen metronome marks with one decimal only in printed sheet music (using typical classical notation) by Karlheinz Stockhausen until now. Moreover, I see an usecase to enter a 'high resolution metronome mark', in allmost unhearable steps, when someone is composing a soundtrack for a silent movie (by rendering the midi file to wav and then adding it to the mp4 file). There the user should add a 'cue point' at the intended 'musical sound effec' to the midi file, and an external program should check, if the cue point hits the frame of the video he wants. But this usecase is out of my scope for the relative tempo changes. Another question, Dan: How realistic do you think are 'unstrechable skips' and 'before barline cadenzas' to be implemented in LILYPOND? What I mean: unstrechable skips: * it's 'spring of the grob' is at least 1000 times harder than normal * overridable grob property: width (counted in staff spaces), otherwise a zero width * excluded for determining the min. durarion in a spacing section * optional feature: exclude it's time in midi output (on/off), but this effect could be done by a tagging it and using removeWithTag in the score with midi output, too before barline cadenzas: * when you insert a (standard) candenza at the place where a barline is going to be placed (currentBarNumber is incremented), the included notes will appear after the barline. * this 'before barline candenza' should insert the notes before the barline, no line break position before the cadenza (due to a bar line) by default, the (regular) barline (and it's increment of currentBarNumber) is placed after the cadenza. A Ceasura with a short wait time in the midi output then could look like this: { c'1 \ceasura % no bar line here \beforeBarlineCadenza \unstretchableSkip 2 % duration; not visible in the sheet music \cadenzaOff % here comes the regular bar line d'4 f' g' b' c''1 } These two suggested features could also be used to place clef change, time signature change and key change between 'repeat end' bar and 'repeat start' bar, which is an example in 'Behind Bars' (on page 253 of the german translation) ArnoldTheresius
