The earliest origins of the tenor guitar are not clear, but it seems unlikely that a true four-stringed guitar-shaped tenor guitar appeared before the late 1920s. Gibson built the tenor lute TL-4 in 1924, which had a lute-like pear-shaped body, four strings and a tenor banjo neck. It is possible that similar instruments were made by other makers such as Lyon and Healy and banjo makers, such as Bacon. In the same period, banjo makers, such as Paramount, built transitional round banjo-like wood-bodied instruments with four strings and tenor banjo necks called tenor harps. From 1927 onwards, the very first true wood-bodied acoustic tenor guitars appeared as production instruments made by both Gibson and Martin.