What is this thing called Tom Waits? Is he a musician? A poet? Is he an actor playing a part? Is he a part playing an actor? Is he an inside joke? An acquired taste? Is he Art?

After eleven albums, seven movies and a play, the answers seem no more obvious than they were in 1973, when Waits growled onto the music scene with a record called Closing Time. If anything, the issue seems more clouded than ever. A recent anthology of tunes from his earlier years shows that, at one time, Waits was doing his best to assimilate his ambitions into the real world. Most of his songs, no matter how subversive and dwarf-ridden, at least sounded like what any guy on the street would recognize as songs.

His last two albums, however - Swordfishtrombones and Rain Dogs - sounded more like soundtracks to avant-garde musicals that were never (thank God) written or produced or cast. Full of powerfully weird images, transmuted vocals and improbable instrumentation - a "junkyard orchestra", Waits called it - the two discs forced Waits to move from folkie, mainstream Elektra Records to smaller, risk-taking Island Records. His new record for Island, Franks Wild Years, is the soundtrack to a musical play that was written (by Waits and his wife, playwright Kathleen Brennan), produced (last summer, by Chicago's Steppenwolf Theatre) and cast (with Waits playing Frank), but it will probably be a long time before most people see the stage version. And perhaps "musical play" is too tame a description, because Franks Wild Years, like Waits himself, doesn't fit easily into any genre.

"I hate musical theatre ," Waitsw barks and coughs, as he does throughout the intervirew," White people standing onstage and singing about cornfields and covered wagons. I hate it. We called it this "un operachi romantico". That's just sometbing Kathleen and I came up with. But it's not like I'm studying opera or anything,. This is just one of my own demented adaptations of things I've seen and heard and remembered. Actually, what I like most about the old recordings of opera is the scratches as much as the music."

"Does this make me an opera singer? Can a dog really sing opera? I don't know. But most of the comparisons with Caruso, I think, are unfair."

Unfair, but maybe apt. Because the music Waits is creating these days makes the most sense when thought of as some new, bastard form of opera. The pieces can no longer be mistaken for pop songs at all. And while Waits' voice has certainly been ravaged by his 37 years (especially the ones he spent living in the notorious Tropicana Motor Hotel in West Hollywood), his recent vocal experimentations may very well lay the groundwork for the next innovations in singing. It's not that many singers will ever cop his technique of crooning through a police bullhorn as he does on Franks Wild Years.But Waits has been pushing and bending his vocal instrument the same way that the computer chip and MIDI (an electronic-instrument "language") have allowed musicians to reinvent "playing".

"I've tried singing through pipes and trumpet mutes, singing into drinking glasses, cupping your hands, things that have been done before," Waits explains, "You can call up a lot of these sounds through technology, but I'm discovering that if I find something myself and nail it to the wall, then it's mine."

"But I don't really think of the music as all that risky. I'm not going to commit musical suicide. But maybe I've got one eye closed. Maybe I don't see the rock coming through the window."

Waits laughs and coughs. "You think maybe I should record with a security guard?" he says, lowering his voice to describe the scene as it might come across on a police-band radio: "Well, he's doing risky music...the band is heavily armed and they've bolted the door and they're in there working with harmonium and bass saxophone...Send the SWAT teams in with tear gas and get them out of there...."

Waits, of course, sees himself as too mainstream. "I think I don't take enough chances," he says, suddenly quite serious. "I'm too much of a sissy. I'd like to go out there and live out there...wherever out there is. You know, a little 'Dr. Livingstone, I presume.' "

But what about the public's perception that he has always been "out there"?

"Well," he says, "The grass is always, uh, browner on the other side of the fireplace."

The suggestion, of course, is that the drunken Beat persona Waits created for himself during his "wild years" - back when he dated Beatress Rickie Lee Jones and closed a lot of bars and diners that he wrote about in songs like "The Piano Has Been Drinking (Not Me)" - is now just one of the characters he's created. Though Waits doesn't much like to talk about his private life, he has been married for seven years and has two children, a daughter named Kellesimone and a son named Casey. While his improved family life may deserve part of the credit (or blame) for his recent musical departures, Waits' experience in film acting may have had more of an impact on his musical and poetic output.

"In some way, acting and working in films has helped me in terms of being able to write and record and play different characters in songs without feeling like it compromises my own personality or whatever. Before, I felt like this song is me, and I have to be in the song. I'm trying to get away from feeling that way, and to let the songs have their own anatomy, their own itinerary, their own outfits," Waits said in an unusual seventeen page interview, instead of the standard three-page biography, that was released to reviewers of his new album. (This is a new trend in the record business; especially risky ventures are now often mailed to reviewers with lengthy "explanations" by the artist. When A&M released Joe Jackson's instrumental Will Power, the record company sent out a Q & A press release and followed it up with a transcript of a speech Jackson had given about the record at a school.)

Waits' movie career began as a strictly musical venture. He wrote the title song for the Ralph Waite film On The Nickel (the track also appeared on his 1980 album Heartattack and Vine, along with his now-revered tune "Jersey Girl"), and he appeared in both Paradise Alley and Wolfen as a piano player. In 1980, he also got involved in Francis Coppola's infamous One From the Heart. Waits worked on that film's score, which Coppola referred to as a "lounge operetta," for eighteen months. Rescued from the piano he kept in his kitchen at the Tropicana, Waits was given space at Coppola's Zoetrope Studios. "That was like being at a university," Waits remembers. He had an office, with a piano, that he came to every day. He got memos. For quite a while, his life was very structured. The movie, of course, bombed, but Waits got an Academy Award nomination for his sound track.

The association with Coppola landed Waits two more film roles, the pool hall proprietor in Rumble Fish and the manager of Coppola's Cotton Club. (He claims that the title of one of the most haunting tunes on Franks Wild Years, "Yesterday Is Here" - "...today is grey skies/tomorrow is tears/you'll have to wait till yesterday is here" - was given to him by Fred Gwynne during a break in Cotton Club's filming.) Last year, he had his first starring role, playing against John Lurie in Jim Jarmusch's cult hit Down By Law. Jarmusch also used one of the tunes from Waits' album Rain Dogs, the driving "Jockey Full of Bourbon", as the picture's title track.

Next month, however, Waits will be seen in his first major role in a mainstream film. He'll play Rudy in the screen adaptation of William Kennedy's Ironweed, which also happens to star Jack Nicholson and Meryl Streep. Waits co-wrote a song for the film - "I wrote the music to a little thing William Kennedy saw scrawled on the side of a bridge twenty years ago in Albany." But, in a way, Ironweed is the first time he's ever played a role in a film, rather than just played himself.

"I was kinda a dark horse for the part," he says, his tone turning much more reverential when the topic of acting comes up. "I had to fly to New York and try out for it. The character is Nicholson's sidekick, an important character. I had to read and all that. But Nicholson was great. During the audition he came up to me and said, "Boy, I hope you don't know your lines, because I sure don't know mine."

Waits took the role seriously and didn't presume that real screen acting would come easily to him. "I have somebody that helps me out privately a little bit (with the acting)," he admits, "Y'know, I was very nervous about it, and I thought I needed a shot in the arm."

Waits is unclear about what he'll do after the film's Christmas release. "I want to try and do something with a much harder edge, something with more abandon," he says, "I may possibly employ more technology. I still like bangin' on trash cans and all that, but I may try something else. I do like a lot of this rap stuff. Maybe even something with big amps, I don't know."

Besides another record of his own, Waits also has a collaboration in the works with avant-garde playwright and director Robert Wilson, who worked two years ago with David Byrne on the critically acclaimed piece The Knee Plays. "I've been talking to Robert Wilson about sort of a cowboy opera of some kind that he's designing in his mind, to be done in Munich," Waits says, "He lives somewhere between Waco and Berlin in his head, and he has a tremendous following in Germany. He's like Da Vinci over there."

This month, Waits and the band that played on Franks Wild Years will be touring the United States. They'll perform restructured versions of the pieces on the record - "You kind of have to surgically implant the play inside the songs" - as well as material from all the older albums. (If you don't own any Tom Waits records, I'd suggest you start with the Elektra anthology and Rain Dogs.) In concert, Waits is much looser than on record, and his agony and ecstacy often give way to sheer hilarity. On his last tour, he showed up more than an hour late for a New York concert and offered as an apology, "I was shampooing my dog...and he likes to have a moisturizer too. Once you start with the toiletries, there's no end in sight."

Since Waits appears to be cleaning up his act somewhat, not to mention his dog, perhaps his fans could use a makeover themselves. "I think I'm gonna have a dress code for the audience," he says, "Boy, they come looking so terrible sometimes. They embarass the hell out of me, you know. I'd like to talk to each one of them about it individually, sweaters and that type of thing. I think they need some fashion consulting. We're gonna come up with something - maybe a different fashion idea on each ticket. We'll get Eldridge Cleaver to come up with something."