sentences:  All four companies advertised extensively, but in contrast to its competitors, only Gibson promoted their mando-bass in photographs of musicians playing it in large groups, emphasizing the social aspects of playing their instrument.Ultimately, the two most successful instruments were those produced by Gibson and Vega.Gibson designed their mandobasses to play either upright or on their side (like a regular mandolin) through changing of the position of the pins the instrument rests on.