Biosphere refer to regions of the earth(sphere) that supports life. It is made up of biotic and abiotic components. Its abiotic components are non-living components that support life and is made up of the lithosphere (the earth crust,mantle) , atmosphere(area of gases and air which is held by gravitational force) and the hydrosphere(all water bodies which includes ocean, sea, lakes, rivers etc).
The sound of the drumstick hitting the metal bar will get to me in a shorter amount of time in Scenario 1 . The sound wave will travel faster in the metal bar than through the air because the speed of sound waves in solid is faster than it is in gases.