Double basses with high Cs are fairly uncommon, and while they do exist, 5 strings with low Bs (sometimes tuned to C) are the most common way orchestral bassists in Europe reach low notes; in the US, UK, and Canada it's more common to see C-extensions.5 string upright isn't too uncommon. They used them in orchestral music depending on the piece. More commonly with high C and they would add low extensions to the E string by the headstock for lower notes.


