In the Theravada tradition there are, at least, two schools regarding the Jhanas: the Visuddhimagga school and the Sutta school.
The Visuddhimagga (800 years after the Buddha) school presents a type of Jhanas (with five items for Jhana 1) that are very difficult to attain. If we expend the Visuddhimagga statements about the chance to get into Jhana 1 we have a probability of something like one in a million. So lay people and many monastics have a bit of a challenge to get there.
The Sutta school (list of some teachers: Thailand: Ajaan Lee, Sri Lanka: Ven. Nannarama Thera, U.S. Thanissaro Bhikkhu, Leigh Brasington, Germany/Australia: Ayya Khema, U.K. Rob Burbea) presents a more “doable” type of Jhanas (with four items for Jhana 1). For this type of Jhanas vitaka-vicarra is of the type I describe in my original posting.