▁similar ▁content . ▁ ▁Audio ▁DVD ▁Tree ▁volumes ▁consisted ▁of ▁about ▁two ▁sets ▁of ▁the ▁T anger ine ▁Tree ▁volumes ▁on ▁a ▁DVD ▁that ▁played ▁to ▁a ▁sl ides how ▁of ▁the ▁CD ▁art work . ▁These ▁releases ▁were ▁standard ▁DVD s ▁with ▁a ▁menu ▁structure ▁and ▁were ▁available ▁in ▁both ▁P AL ▁and ▁N T SC ▁versions . ▁ ▁History ▁For ▁almost ▁four ▁dec ades , ▁much ▁of ▁this ▁material ▁had ▁been ▁trad ed ▁on ▁an ▁inform al ▁basis ▁and ▁many ▁were ▁sold ▁as ▁boot leg s . ▁Much ▁was ▁un ident ified , ▁mis ident ified , ▁low ▁quality ▁and / or ▁a ▁multiple ▁generation ▁copy . ▁T apes ▁were ▁starting ▁to ▁deg rade , ▁as ▁many ▁were ▁as ▁much ▁as ▁forty ▁years ▁old . ▁In ▁the ▁late ▁ 1 9 9 0 s , ▁several ▁collect ors ▁created ▁the ▁Digital ▁T ape ▁Tree ▁project ▁and ▁distributed ▁the ▁material ▁on ▁CD - R . ▁Collect or ▁He iko ▁He ers sen ▁received ▁permission ▁from ▁T anger ine ▁Dream ▁as ▁long ▁as ▁there ▁was ▁no ▁commercial ▁g ains ▁from ▁the ▁project ▁and ▁on ▁ 9 ▁January ▁ 2 0 0 2 ▁began ▁to ▁make ▁appe als ▁on ▁the ▁T anger ine ▁Dream ▁discussion ▁group ▁to ▁gather ▁all ▁of ▁the ▁material ▁together ▁and ▁create ▁a ▁formal ▁project ▁that ▁would ▁use ▁the ▁best ▁available ▁sources ▁to ▁provide ▁the ▁definit ive ▁version ▁of ▁each ▁recording . ▁A ▁large ▁number ▁of ▁previously ▁unknown ▁record ings ▁were ▁discovered ▁and ▁included ▁in ▁the ▁project . ▁All ▁of ▁the