Question

A plucked string instrument that does not have a fingerboard on which to press the strings. Rather, the strings are stretched tightly in the air and they are plucked by both hands while a series of foot pedals are depressed or released in order to change the pitches.

Answer 1

Pedal Harp
A large, technically modern harp, can be played solo or as part of an ensemble

Answer 2

Perhaps a harp?

Step-by-step explanation:

I'm not sure if harps have foot pedals, but they otherwise meet all of the criteria posted here.