The Hadra: Is the group dhikr with singing of poetry and rhythmic swaying permitted?

In the Name of Allah, Most Merciful & Compassionate

Yes, the hadra is in itself permitted, as writings of major Hanafi authorities make clear.

Among the imams of the Hanafi school who have specifically permitted it are Shaykh al-Islam Ibn Kamal Basha, Imam Shurunbulali, Sayyidi Abd al-Ghani al-Nablusi, `Allama Abd al-Qadir `Isa—who cites proofs for it from the major Hanafi reference works, including Ibn Abidin—and Imam Ashraf Ali al-Tahanawi in his Imdad al-Fatawa (5.151).

It is simply one way of fulfilling the general sunna of group dhikr, the general and unconditional encouragement for which is authentically established through numerous hadiths of the Messenger of Allah (peace and blessings be upon him).

Faraz Rabbani.

Please also see the following links in answer to your question:

The Sufi Hadra

Gatherings of Dhikr

An Analysis of the evidence supporting the permissibility of Majalis (gatherings) of Zikr in the Masajid