Playing = false
Time = 0
while true do
    if Time > 155 then
        shell.run("tape rewind")
        Time = 0
    end
    if (Playing == true and redstone.getInput("back") == false) then
            Playing = false
            shell.run("tape stop")
            os.sleep(5)
            Time = 0
    end
    if (Playing == true and redstone.getInput("back") == true) then
        os.sleep(5)
        Time = Time + 5
        Playing = true
    elseif (redstone.getInput("back") == true and Playing == false) then
        Time = 0
        shell.run("tape rewind")
        shell.run("tape play")
        Playing = true
        os.sleep(5)
    else
        Playing = false
        os.sleep(5)
    end
end