Short answers, pulled from the story.
Nettl proposed that the xylophone originated in southeast Asia and came to Africa around AD 500 when a group of Austronesian speaking peoples migrated to Africa. Ethnomusicologist and linguist Roger Blench posits an independent origin of the xylophone in Africa citing distinct features of African xylophones as evidence for local invention.
The Toba Batak people use wooden xylophones known as the Garantung while Java and Bali use xylophones called gambang Rindik and Tingklik in gamelan ensembles. A pentatonic instrument common to Gur-speaking populations exists in Ghana Burkina Faso Mali and Ivory Coast under the name Gyil.
The earliest mention of a xylophone in Europe appeared in Arnolt Schlick's Spiegel der Orgelmacher und Organisten published 1511 where it is called hültze glechter. The term xylophone is not used until the 1860s though descriptions existed earlier and the first use of European orchestral xylophone occurred in Camille Saint-Saëns Danse Macabre in 1874.
Red Norvo George Cary George Hamilton Green Teddy Brown Harry Breuer and Harry Robbins were among well-known players of the xylophone during the 1920s and 1930s. Michael Josef Gusikov created five-row xylophone made of 28 crude wooden bars arranged semitones trapezoid shape resting on straw supports and performed garden concerts variety shows as novelty act at symphony concerts.
Zimbabwean musician Dumisani Maraire brought music to the West coming University Washington 1968 establishing a main event community known as ZimFest annual Zimbabwean Music Festival held each year. Andrew Tracey notes marimbas introduced Zimbabwe 1960 and Shona-based transcriptions adopted original use playing mbira dzavadzimu nyunga nyunga matepe music in Western education systems.