Guitarist and singer-songwriter Ben Harper is on the phone from Los Angeles, where he¡¯s rehearsing for a ¡°small gig¡± at a benefit show hosted by his friend, actor Ed Helms. Harper¡¯s contribution to the concert will be ¡°three or four songs,¡± and when asked if Helms will be doing something comedic on stage ¡ª his best known role is probably in the ¡°Hangover¡± film series ¡ª Harper demurs: ¡°Ed is a badass banjo player, actually.¡±

That is probably one of the highest compliments Harper could bestow on someone, since he¡¯s made a career out of promoting styles of music that tend to sink or swim on an artist¡¯s command of what jazz musicians used to call ¡°chops.¡±

Harper himself is one of the most accomplished acoustic, slide and lap steel guitarists in the business, playing his instruments in the service of what is generically called roots music, a wide category that includes blues, folk, reggae and soul, genres he has moved among with ease and confidence ever since debuting in the early ¡®90s. He¡¯ll be bringing the whole mess, along with his longtime backing band, The Innocent Criminals, to Japan in March for his first tour of the country in 14 years.