The new year got off to a remarkable start when Johanna Meier sang her first Metropolitan Opera Isolde Jan. 3. The soprano has been Bayreuth's Isolde for the past three summers (the first American to ever sing the role in Wagner's own theater). That production of ''Tristan und Isolde'' was filmed for international television this past October. She has sung in Mexico City, Toronto, Venice, and with Sir Reginald Goodall and the Welsh National Opera and will be introducing her interpretation to Vienna in 1985.
Because of her fine work first at the New York City Opera and later at the Met, Miss Meier has been known as an unusually insightful, elegant artist. Her rich soprano is capable of riding a full orchestra without losing quality and sheen in the title role of Strauss's ''Ariadne auf Naxos'' while capable of an enchanting youthfulness as Marguerite in Gounod's ''Faust.''
Despite her acclaim in the role the world over, her Met Isolde came as a revelation: The voice has grown in potency and luster; it can now ride the full Wagner ensemble at the Met, while her quiet singing remains ravishing and haunting.
This Isolde does not try to create a flooding of sound and the stentorian delivery that were Birgit Nilsson's trademarks. Rather, Miss Meier makes the Irish princess a complete woman - warm, passionate, feminine, tempestuous, beguiling, and clearly and always of royal blood. Her stage demeanor is ravishing, her movement graceful, lithe. She projects her words with uncommon attention to meaning and to coloration.
There is a good deal of this characterization that is sung quietly, introspectively, which is a throwback to the way the role must have been sung before the truly huge voices took it over in the '30s. The concluding ''Liebestod'' - where so many sopranos ultimately founder - took wing memorably, filling the house with gorgeous sound that easily rose over the orchestra.
As to the rest of the performance, there was Manfred Jung's underscaled Tristan, Martti Talvela's dramatically effective but vocally askew King Marke, and Richard J. Clark's woolly, strident Kurwenal. Lorna Myers was making her debut as Brangane, and when she was not pushing, the voice had size, and a rich contralto presence. In the pit, James Levine might have been more considerate of his singers in terms of dynamics and tempos but the orchestra played handsomely.
A few days before her first Met performance I had a chance to talk with her about the role. At that time she told me, ''I have been doing it now for five - almost six - years. I had the great fortune, when I began to work on the role, to be asked to do a series of performances with the Welsh Opera, and thereby to work through the role with Reginald Goodall. (Goodall is considered one of the finest Wagnerians alive today, having learned the repertoire as assistant to both Wilhelm Furtwangler and Hans Knappertsbusch, two of the greatest Wagnerians of all time.) That was a marvelous experience and I think (it) really solidified the role for me.
''The work with him basically established my thought about the role and my approach to it - which is probably a much more lyric approach. He called my attention to the fact that page after page of the score is marked piano. We are not used to that kind of treatment either orchestrally or vocally. (Goodall) actually did keep the orchestra down to a piano, and I have worked since in productions where that kind of lyric concept was acceptable. That was certainly what Daniel Barenboim strove for in Bayreuth, which made that situation very much more comfortable for me.''
About her approach to singing the heavier literature in general, she first notes, ''I am by no means jumping into the deep waters of hochdramatisch (full dramatic) soprano. If there is a role which can be approached lyrically which is in the dramatic repertoire, and which I feel is approachable and possible for me to do in that way, then I'll do it.
''I am not interested in making an enormous sound. I'm much more interested in the context of what I'm singing - in the words, and the meaning, and what color I can put into them. So I am very much taken with roles that can offer me that. Isolde is one of the great acting roles; you see so much of her, in so many aspects. Having done it a number of times - I'm now at my 65th or so performance - I feel I continue to learn and rework it. I don't think in a role like that you can ever stop. It's never a role you can take for granted.''
When she first sang the role at Bayreuth, Miss Meier made the newspapers for having said no to director Jean-Pierre Ponnelle's decision to put Isolde in the orchestra pit for the last act. (Ponnelle's ''re-interpretation'' has Tristan only imagining that Isolde returns: Contrary to Wagner's ending, Tristan dies alone, abandoned - even the ''Liebestod'' being a hallucination.)
As it turned out, the sound Ponnelle thought he could achieve did not happen in Bayreuth's famous covered pit.
Next season, Miss Meier sings Chrysothemis in Strauss's ''Elektra'' at the Met. She also will be adding the same composer's Salome to her repertoire in a production at Rouens, France, which then moves to Marseilles, followed by a new production in Hamburg. She sings regularly at the Vienna State Opera, and she will be in Bayreuth singing Isolde when the production returns in '85.
Last year she added Minnie in Puccini's ''La Fanciulla del West,'' and this year will have a chance to sing Norma again. She is talking about the Empress in Strauss's ''Die Frau ohne Schatten'' in a couple of years.
So while her career is indeed heading toward heavier repertoire, she is not abandoning - and hopes to never have to abandon - the lighter Italian repertoire. ''If I continue along these lines, with mingling repertoire, I think that's going to hold me comfortably.''