Metronomic indications

Metronomic indication deserves a special macro. The mention:

60

is coded by normalshapemediumseries normalshapemediumseriesnormalshapemediumseries\metron{ normalshapemediumseries\hup} { 60} (normally embedded in normalshapemediumseriesnormalshapemediumseries\Uptext which is in turn embedded within normalshapemediumseries\ notes...normalshapemediumseries\enotes).