He joined with a group vocal as percussion and then tried to play guitar and sing while playing harmonica. He then moved and starts to play bass. His enthusiasts to learn this large string instrument starting to get serious when he met Bintang Indrianto. Then Indro came to Indra Lesmana to study more about music and also to Erwin Gutawa and a saxophonist Maryono. Indro Hardjodikoro has now become the best bassist session player in Indonesia. He has experienced in recording from Pop, Jazz and any other type of music for various Artists in Indonesia. His appearance in TV is also very often, such as Indonesian Idol and other music program in station TV in Indonesia. Indro also experienced played with international musicians such as Kenny Garret, Dave Koz, Michael Lington, Michael Colina. Master class in Rhythm and Groove Music Camp with Victor Wooten. He has also jamming with Herbie Hancock in Bali, George Duke, Mattias “IA” Eklundh (Laney endorser). Recording session with several international musicians, such as: Earnie Adams (drum), Howard Levi (Harmonica), Frank Gambale (guitarist) in Dwiki Dharmawan World Peace Orchestra, Sheila Madjid solo album, Bob Sheppard (saxophone), Dira J. Sugandi album which is produced by Bluey Incognito. Indro is now Markbass international artists, endorsed by Cort Signature Series 4, 5 and 6 strings and is also using Fodera 6 strings. Indro Hardjodikoro is also active in education. He has become Head of Bass Department in Institute Music Indonesia (IMI) the first Contemporary Music Institute in Indonesia.