Incorrect duration of gradual tempo changes (accel. and rit.)

[torstenanders]

It seems there is a problem with the notation and MusicXML export of the "duration" of gradual tempo changes. The end of the tempo changes is shown too early, already at the beginning of the bar specified as its duration. (If a longer duration is specified to correct for that, then all subsequent tempo changes are delayed accordingly.)

   

In the following example, the initial accellerando should last for 4 bars, but the final tempo q=200 is already displayed in the notation output at the beginning of bar 4, i.e., after 3 bars. Note that the tempo changes in the playback are correct, but the notation is not (nor the tempi in the exported Sibelius file).

 

(setf pitches (gen-repeat 20 '((c4 d4 f4 g4))))

(setf tempo
      '((q :accel 70 200 1/32 4)
        (110 1)
        (:rit 100 60 1/32 2)
        (120 1) (60 1) (120 1) (110 1)
        ))

(def-score test-tempo
           (:key-signature 'chromatic
            :time-signature '(4 4)
            :tempo tempo)
  
  (inst
   :omn (make-omn :pitch pitches
                  :length (span pitches '(1/8)))
   :channel 1
   :sound 'gm
   :program 'Clarinet))

 

By the way, the documentation of the tempo argument of def-score seems to suggest that the duration (argument count) of individual tempo statements can be independent of bars by specifying :length. However, I was not able to specify that. Please see below for a non-working attempt. What am I misunderstanding here?

 

(setf tempo
      '((q 170 :length 3/2)
        (:rit 150 100 1/16 :length 1/2)
        (90 1)
        ))

 

Thanks!

 

Best,

Torsten

[opmo]

This is a bug. 

[torstenanders]

So, are these two bugs? One related to the extend/duration of a rit. etc. and the other to :length?

 

Thanks!

 

Torsten