Simplify the following text for a Grade 7 native English-speaking person.
Original: In 2005 , Gustavo Dudamel first conducted the Gothenburg Symphony at the BBC Proms , on short notice as a replacement for the indisposed Neeme JÃ rvi .
Simplified: In 2005 , Gustavo Dudamel conducted at the BBC Proms when Neeme JÃ rvi was ill. .