Howard F. answered 08/20/20
DMA in Theory/Comp with 20+ Years of Teaching Harmony + Counterpoint.
Some instruments can play a lower range of pitches than some voices.
It all depends on which instrument you're playing and what voice type is singing.
Singers are usually categorized (from high to low) as sopranos, altos, tenors or basses (with some other types in between).
Instruments can have a very high pitch range, like a flute or piccolo, or a very low pitch range, like a bass guitar, or tuba. And there are some, like piano, that can play across a wide range of pitches.
So the answer to your question is it depends on the type of voice (and the individual singer), as well as which instrument you're playing. There are definitely examples of instruments that can play lower than any singer can sing. Certainly, a piano is one of those instruments. A contrabassoon is another such instrument.
Hope that makes it clear and simple to understand!
Feel free to ask more questions.