The solo and chorus, "Come, if you Dare," is to this day one of the most stirring and effective displays which a tenor vocalist could select, and is therefore frequently heard. The whole of the frost scene is remarkable from its vocal realism of intense and freezing cold. The peculiar and original effects here introduced by Purcell were afterwards copied by Jeremiah Clark, a fellow-student of Purcell, in the anthem, "I will love Thee, O Lord." Mention must also be made of the lovely duet, "Two daughters of this aged stream." Unfortunately no complete copy of the score of this work, the outcome of the composer's mature judgment, exists. It is presumed that Purcell wrote only one perfect copy, which was retained by the managers of the theatre, who, jealous of possible rivals, would neither permit it to be copied in manuscript or printed.[39] The success at the time of its production is thus recorded by Downes in his _Roscius Anglicanus_:-- "_King Arthur_, an opera, wrote by Mr. Dryden; it was excellently adorned with scenes and machines: the musical part set by the famous Mr. Henry Purcell, and Dances made by Mr. Jo. Priest: the play and musick pleas'd the Court and City, and being well perform'd 'twas very gainful to the company." Dryden's courtly servility has been deplored by more than one author. He had followed the lead set by Charles II., who had imported Monsieur Grabu from France, and set him up as a musical king, and for him, by royal command, Dryden wrote the opera of _Albion and Albanius_. In the preface to the work he says:-- "The best judges, and those too of the best quality, who have honoured his (Grabu's) rehearsals with their presence, have no less commended the happiness of his genius than his skill. These and other qualities have raised M. Grabu to a degree above any man who shall pretend to be his rival on our stage." The composer who was thus set above Purcell appears to have enjoyed a somewhat exalted opinion of his own ability, as will be seen by the following extract from the dedication of _Albion and Albanius_, addressed to James II. by Grabu himself:-- "As the subject of this opera is naturally magnificent, it could not but excite my genius, and raise it to a greater height in the composition--even so as to surpass itself. The only displeasure which remains with me is, that I could not possibly be furnished with variety of excellent voices to present it to your Majesty in full perfection."