TO BLOW SOMEONE'S OWN TRUMPET

TO BLOW SOMEONE'S OWN TRUMPET IS NOT A MUSICAL FACT. WHEN YOU ARE BLOWING YOUR OWN TRUMPET, YOU ARE EXAGGERATING FACTS, INFORMATION, ... ALWAYS TO BENEFIT YOURSELF, TELLING OTHER PEOPLE HOW GOOD AND SUCCESSFUL YOU ARE.
"TO BLOW SOMEONE'S OWN TRUMPET" MEANS ALARDEAR OR PRESUMIR DE SÍ MISMO.