The term 'Xylophone Relative' refers to three different instruments: the MARIMBA (7 letters), glockenspiel (12 letters), and sticcado (8 letters). The MARIMBA is a percussion instrument of African origin, consisting of wooden bars struck with mallets. The glockenspiel is a percussion instrument composed of a set of tuned metal bars played with small hammers. The sticcado is a type of xylophone that originated in South America and is made from bamboo tubes. All three instruments are related to the xylophone, as they all produce sound by striking tuned bars.