Instruct: Classify the given review as either positive or negative.
Query: Ian Anderson in top form

Jethro Tull from time to time in their career have made milestone albums that have defined them. Among those albums would be Aqualung, Thick as a Brick, The Minstrel in the Gallery, Heavy Horses, Songs from the Wood, The Broadsword and the Beast, Crest of a Knave and Rock Island.Ian Anderson is on stride and his interplay with Martin Barre on guitar is outstanding. Ian Anderson with his flute and Barre on the guitar play what amounts to duel lead on their recordings.Among the songs are Undressed to Kill, Rock Island, Heavy Water, Another Christmas song and my personal favorite Whaler's Dues. Whaler's Dues is in my mind one of the finest songs Ian Anderson has ever wrote and my ears always perk up when it plays.Ian Anderson has put together a masterpiece that not only Tull collectors will love, but Classic Rock fans as well. This is Jethro Tull in its top form and a very nicely crafted album to say the least...................