Simplify the following text for a Grade 10 native English-speaking person.
Original: In the Classical era , the double bass typically doubled the cello part an octave below , occasionally requiring descent to C below the E of the four-string double bass .
Simplified: Throughout classical repertoire , there are notes that fall below the range of a standard double bass . Notes below low E appear regularly in double bass parts in the Baroque and Classical eras , when the double bass was typically doubling the cello part an octave below .