Simplify the following text for a Grade 10 native English-speaking person.
Original: After Bill Kaulitz 's participation in a children 's Star Search in 2003 at age thirteen ( which he lost in the quarter-final ) , he was discovered by music producer Peter Hoffmann .
Simplified: After Bill Kaulitz took part in a children 's Star Search in 2003 at age thirteen ( which he lost in the quarter-final ) , he was discovered by music producer Peter Hoffmann .