Square fermata, a boxy angular hold sign over a note meaning sustain it longer.
U+1D26CMUSICAL SYMBOL DOUBLE TRIANGULAR FERMATAU+1D26EMUSICAL SYMBOL DOUBLE SQUARE FERMATAU+1D26BMUSICAL SYMBOL TRIANGULAR FERMATAU+1D26FMUSICAL SYMBOL HENZE LONG FERMATAU+1D26AMUSICAL SYMBOL DIAMOND NOTEHEAD HALF-FILLEDU+1D270MUSICAL SYMBOL HENZE SHORT FERMATAU+1D269MUSICAL SYMBOL DIAMOND NOTEHEAD BLACKU+1D271MUSICAL SYMBOL CURLEWU+1D268MUSICAL SYMBOL DIAMOND NOTEHEAD WHITEU+1D272MUSICAL SYMBOL SALZEDO BREATH MARKU+1D267MUSICAL SYMBOL DIAMOND NOTEHEAD WHOLEU+1D273MUSICAL SYMBOL ORGAN PEDAL HEEL50 characters in the Musical Symbols Supplement Unicode block.
U+1D250MUSICAL SYMBOL COMBINING FLAG-6U+1D251MUSICAL SYMBOL COMBINING FLAG-7U+1D252MUSICAL SYMBOL COMBINING FLAG-8U+1D253MUSICAL SYMBOL TWO HUNDRED FIFTY-SIXTH RESTU+1D254MUSICAL SYMBOL FIVE HUNDRED TWELFTH RESTU+1D255MUSICAL SYMBOL ONE THOUSAND TWENTY-FOURTH RESTU+1D256MUSICAL SYMBOL FLAT WITH STROKEU+1D257MUSICAL SYMBOL FLAT WITH DOUBLE STROKEU+1D258MUSICAL SYMBOL FLAT WITH DOUBLE STEMU+1D259MUSICAL SYMBOL HALF SHARP WITH STROKEU+1D25AMUSICAL SYMBOL SHARP WITH STROKEU+1D25BMUSICAL SYMBOL COMBINING TREMOLO-4U+1D25CMUSICAL SYMBOL COMBINING TREMOLO-5U+1D25DMUSICAL SYMBOL FINGERED TREMOLO-4U+1D25EMUSICAL SYMBOL FINGERED TREMOLO-5U+1D25FMUSICAL SYMBOL COMBINING BUZZ ROLL STEMU+1D260MUSICAL SYMBOL TRIPLE FLATU+1D261MUSICAL SYMBOL SUSPENSIONU+1D262MUSICAL SYMBOL HEAVY DOUBLE BARLINEU+1D263MUSICAL SYMBOL SYSTEM DIVIDERU+1D264MUSICAL SYMBOL NIENTEU+1D265MUSICAL SYMBOL CRESCENDO WITH RINGU+1D266MUSICAL SYMBOL DECRESCENDO WITH RINGU+1D267MUSICAL SYMBOL DIAMOND NOTEHEAD WHOLEU+1D268MUSICAL SYMBOL DIAMOND NOTEHEAD WHITEU+1D269MUSICAL SYMBOL DIAMOND NOTEHEAD BLACKU+1D26AMUSICAL SYMBOL DIAMOND NOTEHEAD HALF-FILLEDU+1D26BMUSICAL SYMBOL TRIANGULAR FERMATAU+1D26CMUSICAL SYMBOL DOUBLE TRIANGULAR FERMATAU+1D26DMUSICAL SYMBOL SQUARE FERMATAU+1D26EMUSICAL SYMBOL DOUBLE SQUARE FERMATAU+1D26FMUSICAL SYMBOL HENZE LONG FERMATAU+1D270MUSICAL SYMBOL HENZE SHORT FERMATAU+1D271MUSICAL SYMBOL CURLEWU+1D272MUSICAL SYMBOL SALZEDO BREATH MARKU+1D273MUSICAL SYMBOL ORGAN PEDAL HEELU+1D274MUSICAL SYMBOL ORGAN PEDAL TOEU+1D275MUSICAL SYMBOL G CLEF OPTIONALLY OTTAVA BASSAU+1D276MUSICAL SYMBOL DOUBLE G CLEFU+1D277MUSICAL SYMBOL G CLEF OTTAVA BASSA WITH C CLEFU+1D278MUSICAL SYMBOL C CLEF OTTAVA BASSAU+1D279MUSICAL SYMBOL G CLEF QUINDICESIMA ALTAU+1D27AMUSICAL SYMBOL G CLEF QUINDICESIMA BASSAU+1D27BMUSICAL SYMBOL F CLEF QUINDICESIMA ALTAU+1D27CMUSICAL SYMBOL F CLEF QUINDICESIMA BASSAU+1D27DMUSICAL SYMBOL C CLEF QUINDICESIMA BASSAU+1D27EMUSICAL SYMBOL TABLATURE CLEFU+1D27FMUSICAL SYMBOL ARPEGGIATO UP WITH ARROWU+1D280MUSICAL SYMBOL COMBINING STEM BOW BEHIND BRIDGEU+1D281MUSICAL SYMBOL COMBINING STEM BOW ON TOP OF BRIDGE