diff --git a/MidiGrid_PlayFromBar.lua b/MidiGrid_PlayFromBar.lua
new file mode 100644
index 0000000..c87f31b
--- /dev/null
+++ b/MidiGrid_PlayFromBar.lua
@@ -0,0 +1,12 @@
+--[[
+  MIDI Grid: play from the start of the bar the cursor is in.
+
+  Deliberately works whether or not grid mode is on -- it is a listening aid,
+  not an editing action, and it is just as useful while navigating with OSARA
+  normally. Stop with Space as usual.
+]]
+local dir = ({ reaper.get_action_context() })[2]:match("@?(.*[\\/])")
+local G = dofile(dir .. "midigrid_lib.lua")
+
+local bar = G.playFromBar()
+G.say("Playing from bar " .. bar)
diff --git a/README.md b/README.md
index dbef4a7..0efd734 100644
--- a/README.md
+++ b/README.md
@@ -81,6 +81,7 @@ actions by hand in Actions → Show action list. That always works.
 | `Alt+Shift+Up` / `Alt+Shift+Down` | Velocity up / down | — |
 | `Alt+G` | **Toggle grid mode on/off** | — |
 | `Alt+H` | Toggle hold mode | — |
+| `Alt+Space` | Play from start of the current bar | works in both modes |
 | `Alt+A` | Repeat current cell (speak + sound) | — |
 | `Alt+S` | Set root and scale | — |
 | `1`–`9` | Grid size — REAPER's own grid actions | same |
@@ -149,6 +150,22 @@ survive. They also need no mode: `L` behaves identically whether hold is on or
 off, so there is no state to set up beforehand and none to remember to turn
 off afterwards.
 
+## Hearing it in context
+
+`Alt+Space` plays from the **top of the bar the cursor is in**, and says which
+bar. Stop with `Space` as usual.
+
+Auditioning a cell tells you what a note *is*; playing from the downbeat tells
+you whether it is in the right *place*. At 16ths or 32nds that difference is
+the whole question, and it cannot be judged from a note in isolation.
+
+Your position is preserved. The edit cursor doubles as the grid cursor, so it
+is moved to the bar line only long enough to start playback and then put
+straight back — you carry on editing exactly where you were.
+
+This one works whether or not grid mode is on, since it is a listening aid
+rather than an editing action.
+
 ## Shifting notes in time
 
 If a whole clip landed a couple of cells off the beat, `Ctrl+Shift+Left` and
diff --git a/install.ps1 b/install.ps1
index 8c32e0a..d74f718 100644
--- a/install.ps1
+++ b/install.ps1
@@ -59,7 +59,8 @@ $actions = @(
     @('RSmidigrid_shl',    32060, 'MIDI Grid: Shift all notes one cell left',   'MidiGrid_ShiftLeft.lua'),
     @('RSmidigrid_shr',    32060, 'MIDI Grid: Shift all notes one cell right',  'MidiGrid_ShiftRight.lua'),
     @('RSmidigrid_shlf',   32060, 'MIDI Grid: Shift all notes left (force)',    'MidiGrid_ShiftLeftForce.lua'),
-    @('RSmidigrid_shrf',   32060, 'MIDI Grid: Shift all notes right (force)',   'MidiGrid_ShiftRightForce.lua')
+    @('RSmidigrid_shrf',   32060, 'MIDI Grid: Shift all notes right (force)',   'MidiGrid_ShiftRightForce.lua'),
+    @('RSmidigrid_playbar',32060, 'MIDI Grid: Play from start of current bar',  'MidiGrid_PlayFromBar.lua')
 )
 
 # flags, keycode, section, id
@@ -86,7 +87,8 @@ $keys = @(
     @(13, 32805, 32060, 'RSmidigrid_shl'),
     @(13, 32807, 32060, 'RSmidigrid_shr'),
     @(29, 32805, 32060, 'RSmidigrid_shlf'),
-    @(29, 32807, 32060, 'RSmidigrid_shrf')
+    @(29, 32807, 32060, 'RSmidigrid_shrf'),
+    @(17, 32,    32060, 'RSmidigrid_playbar')
 )
 
 $backup = "$kb.midigrid-backup"
diff --git a/midigrid_lib.lua b/midigrid_lib.lua
index a331fb3..79463d2 100644
--- a/midigrid_lib.lua
+++ b/midigrid_lib.lua
@@ -352,6 +352,41 @@ function M.toggleCell(take, pitch)
   return result, detail
 end
 
+------------------------------------------------------------------ playback
+
+-- Start of the bar containing time t, plus the 1-based bar number.
+function M.barStart(t)
+  local _, measures = reaper.TimeMap2_timeToBeats(0, t)
+  return reaper.TimeMap2_beatsToTime(0, 0, measures), measures + 1
+end
+
+--[[
+  Play from the top of the bar the cursor is in, without losing your place.
+
+  The edit cursor doubles as the grid cursor, so it is moved to the bar line
+  only long enough to start playback and then put straight back. Restoring it
+  passes seekplay=false so the restore cannot drag playback along with it.
+
+  Playing from the bar line rather than the cursor is what makes fine
+  subdivisions checkable: you hear the note in relation to the downbeat,
+  which is the thing you are actually trying to judge.
+]]
+function M.playFromBar()
+  local here = reaper.GetCursorPosition()
+  local barPos, barNum = M.barStart(here)
+
+  reaper.PreventUIRefresh(1)
+  reaper.SetEditCurPos(barPos, false, true)
+  -- GetPlayState bit 0 is "playing"; avoid bitwise ops for portability.
+  if (reaper.GetPlayState() % 2) == 0 then
+    reaper.CSurf_OnPlay()
+  end
+  reaper.SetEditCurPos(here, false, false)
+  reaper.PreventUIRefresh(-1)
+
+  return barNum
+end
+
 ---------------------------------------------------------------- time shift
 
 --[[