Topmusicanswers
It will all depend on the octave -- the lowest E natural and F# are impossible since they both need to be played on the lowest string C (unless you want to tune the G string down to F#).
Can cellos play double stops?
If you have a big hand, or are very flexible, then you can play the cello more like a violin …… and you can put the double-stops back in! ... And even the minor third hand frame can block and rigidify the hand, making vibrato difficult.
Can cello double stop octaves?
Double-stop combinations that demand left-hand stopped pitches on both strings are more cumbersome for the player to grab. They are usually restricted to intervals of an octave or less in the first two-and-a-half octaves of a string instrument. ... Tenths are possible in the third octave of the violin, viola, and cello.
