Joseph Haule (born December 29, 1975), popularly known as Professor Jay, is a Tanzanian hip hop artist. He is one of the prominent representantives of the "Bongo Flava" Tanzanian hip hop subgenre, which mixes elements from both Western hip hop and the Tanzanian tradition (including swahili lyrics as well as an activist attitude towards Tanzanian social issues such as HIV/AIDS, wealth, inequality, and political corruption).
He started rapping in 1994 as a member of the group Hard Blasters, best known for their hit "Chemsha Bongo" (then he used stage name Nigga J) from their first album, "Funga Kazi". Only one year later, they won the title of best hip-hop group in Tanzania.
During his solo career which he started in 2001, he has released number of hits, including "Nikusaidiaje" and "Zali la Mentali (feat Juma Nature)". Other songs released by Professor Jay include "Piga Makofi" and "Yataka Moyo". Just like Mr. II, he is a pioneering Tanzanian MC, who have remained some of the most popular hip hop musicians in Tanzania, despite influx of many new bidders. Also similar to Mr. II his lyrics often have political messages. In one of his songs he imitates an elder politician and ridicules the fake promises they all mindlessly spew as they are trying to get elected. The song continues with a chorus saying the words "Ndio Mzee" which means "Yes Sir". This represents the brain washing of the public as politicians make these false promises over and over. It is interesting to note however, that after this song was produced, the president of Tanzania referenced the lyrics in one of his speeches, which acknowledged the presence of Bongo Flava and the success of Professor Jay's political lyrics.
His first album, "Machozi, Jasho na Damu," gained instant recognition for which Professor Jay won several awards. He attained other awards such as the best hip-hop album in Tanzania with his second album, "Mapinduzi halisi".
Professor Jay's songs include Nikusaidiaje (featuring Ferooz), Nimeamini (featuring Lady Jaydee), Inatosha (featuring Sugu), Vuta raha (featuring Ferooz), Border kwa border (featuring Nazizi), Heka heka za star, Interlude, J.O.S.E.P.H., Nisamehe (featuring Banana), Wapi nimakosea, Una, Hakuna Noma, Jina Langu, Bongo Dar es Salaam, Piga Makofi, Msinitenge, Sio Mzee, Zali la Mentali, Nidivyo Sivyo, Mtazamo (featuring Afande Sele and Solo Thang), Hapo Sawa. Professor Jay is featured on Nonini's song "Kumekucha" 
His former group Hard Blasters is set for a comeback in 2009. The new lineup will consist of Professor Jay, Big Willy and Fanani. They will release a new album 
- Machozi Jasho na Damu 2001
- Mapinduzi Halisi 2003
- J.O.S.E.P.H 2006
- Aluta Continua 2007
- Izack mangesho 2014
- 2004 Tanzania Music Awards (Kilimanjaro Music Awards)- Best Hip Hop Album ("Mapinduzi Halisi") 
- 2006 Tanzania Music Awards - Best Song (Nikusaidiaje) 
- 2006 Kisima Music Awards - Best Tanzanian Song (Nikusaidiaje)
- 2007 Kisima Music Awards - Best Ugandan Song (Sivyo Ndiviyo with Chameleone) 
- 2007 Pearl of Africa Music Awards (PAM Awards) - Best Male Artist (Tanzania) 
- 2009 Tanzania Music Awards - Best Songwriter 
- Bongo Flava: Swahili Rap from Tanzania
- Professor Jay : BAB KUBWA
- Bongoflava: The Primer - Pop Playground - Stylus Magazine
- Interview: AFRICAN HIP HOP IN TANZANIA - Highlights of a Conversation with Alex Perullo
- Prefessor Jay Discography
- noninin - Mwisho ya Mawazo liner notes
- Swahili Remix, January 2, 2009: Hard Blasters Comeback!
- Tanzania Music Awards - Winner 2004
- Tanzania music Awards 2006 winners
- Kisima Awards winners 2006
- Kisima Awards winners 2007
- Museke: Pearl of Africa Music (PAM) awards 2007 winners - Uganda
- Daily Nation, Buzz Magazine, April 12, 2009: The Kilimanjaro Awards 2009:The highs and lows
- BBC, November 23, 2008: Nigerians sweep MTV Africa awards