Jhana with aum and nimitta

 Morning:

After breakfast at 7.30, did a sitting in hall facing balcony. Did AUM and in the middle syllable - U -, felt the overtone and immediately piti arose in the head.  I abided in it. 

Evening:

At around 3.30 pm, did 3 different meditations. Started with Buddhadasa's anapanasati. Step 1, 2, 3 and 4 (1st tetrad).  1 = Long breath, 2 = short breath, 3 = breath + body (breath is body conditioner) and 4 = calming breath (body conditioner). No piti. At step 4, tried to get nimitta but there was none. Supposed open or half-open eyes and gaze downwards at direction of tip of nose and watch the breath there - to get nimitta. 

Felt sleepy and switched to 2nd meditation which is TWIM/brasington, relax with outbreath, smile and immediately got the piti. Used it to overcome sloth/torpor (one of the 5 hindrances). Body vibrated as usual.

In the last 15 mins, I switched to AUM meditation. Again felt the piti at the second syllable - U - It was in the middle of the head - quite nice.

Summary:

Buddhadasa's explanation on Anapanasati's 16 steps is better than the Bikkhu Bodhi's Majjhima Nikaya. He explains the breath-body conditions physical body. And so we do step 3 to understand how the breath and body are related. Step 1 and 2 are preparatory to step 3. Then, in step 4, we actually try to calm the breath-body (body conditioner) so that the body is calm. The goal of step 4 is to get piti/sukha so that we can do the 2nd tetrad. But to get piti/sukha we need to get a nimitta.