A user tool to change all the tempos in a selection.
Needs a numeric parameter.
A straight number means that the first tempo indication will be set to that value. All the others will be changed by the same proportion.
A percent number multiplies all the tempos by that amount.
Example: 120% means +20%
A signed percent number changes all the tempos by that amount.
Examples: +20% means 120%, -15% means 85%
N.B. This tool ignores the NWC multi point controller called "tempo".