Most complex "block" of sheet music notation

Question

Wondering how complex a single piece of sheet music can get, and what it looks like. For example, on the guitar, theoretically you could define the following:

• a chord
• bend from another chord
• bend to another chord
• hold for 3 beats (dot)
• wiggle string

I don't have the music software to write the notation at the moment, but a chord might look like:

or

I'm wondering if you also took into account the following, how complex you can make it look while still being readable and realistic:

• How hard you hit the notes.
• Different sheet music notations for different stringed instruments
• Guitar petal notations.
• Temporary time signature changes.
• Screaming if it is vocals
• Other vocal features.
• Etc.

Those are just some ideas to add to the complexity of the sheet music. But basically I'm wondering how complex sheet music can get when it tries to encode every feature possible.

By "complex" I just mean the visible look of the notation, rather than how hard it is to play. Doesn't matter the instrument, just whatever results in some of the more complex notations you can construct.

Answer 1

It's interesting you use the word "complex." I was hesitant to answer for fear that this question was too opinion-based (and it might still be), but your use of this term made the answer very clear: consider the music (and notation) of the New Complexity movement.

To quote directly from an opening line of the Wikipedia article:

Though often atonal, highly abstract, and dissonant in sound, New Complexity music is most readily characterized by the use of techniques which require complex musical notation. (emphasis my own)

Take, for example, this excerpt from Brian Ferneyhough's "Unity Capsule," which only involves two instruments (played by one performer!):

Ferneyhough is one of the leaders of the New Complexity movement, and any score of his you find will be among the most complex out there.

Answer 2

Among other things, the sheet music might indicate

• a tempo indication (in bold above everything else) e.g. Allegro
• a mood indication e.g. espressivo
• an absolute dynamic, e.g. mf
• a relative dynamic, e.g. poco cresc.
• a phrasing slur
• an articulation mark e.g. . (staccato) or - (tenuto). You sometimes get . and - combined.
• which finger to use
• which string to play on
• (for vocal music) the words