Bṛhad-bhāgavatāmṛta Part 2 Chapter 3 Text 157

ekākitvena tu dhyānaṁ
vivikte khalu sidhyati
saṅkīrtanaṁ vivikte ’pi
bahūnāṁ saṅgato ’pi caTRANSLATION
Meditation one can successfully perform only in seclusion, but saṅkīrtana either in seclusion or in the company of many others.