function playSoundOn(URL,ent)
    sound.PlayURL ( URL, "3d", function( station )
                if ( IsValid( station ) ) then
          timer.Create("tesddd",0.1,0,function()
          for k,v in pairs (ents.FindByClass(ent)) do
                  station:SetPos( v:GetPos() )
        end end)
    station:Play()
        else end
    end )
end

playSoundOn("https://www.dropbox.com/s/rh6j2h402yjmx87/John%20Williamson%20True%20Blue.mp3?dl=1","gmod_sent_vehicle_fphysics_base")