Simplify the following text for a Grade 7 native English-speaking person.
Original: Arp Schnitger ( born July 2 , 1648 in Schmalenfleth , buried July 28 , 1719 ) was a highly influential German organ builder .
Simplified: Arp Schnitger ( born Oldenburg , 2 July ? 1648 ; buried in Neuenfelde , near Hamburg , 28 July 1719 ) was a very important German builder of pipe organs .